TilesetLoader.loadImage() fails with "Image dimensions must be positive" when tiles have custom properties

[omicreativedev]

Describe the bug
TilesetLoader.loadImage() fails with "Image dimensions must be positive" when tiles have custom properties.
The objective was to use Tiled Map Editor to make the JSON map information for use with FXGL.
I admit, I'm new to this so I'm not sure I did it right. Im going to use an object layer instead, but I thought someone might want to look at this anyway

To Reproduce
This happens when using TiledMapEditor (https://www.mapeditor.org/) to generate a map. When using a map with an embedded (or external) tileset, and adding a custom property to the tile, such that the rendered JSON appears to have:

<tile id="1">
   <properties>
    <property name="blocking" type="bool" value="true"/>
    <property name="type" value="map_tile_wall"/>
   </properties>
  </tile>

The map no longer parses.

Expected behavior
I expected the map to parse.
When using a .tmx without any custom properties, it works.

Runtime info(please complete the following information):
Windows 11 Home
Using Java: JDK 21 (LTS), JavaFX: 21.0.1, FXGL: 21.1, Tiled Map Editor: 1.11.2, Maven 3.9.5, Eclipse Version: 2025-12 (4.38.0)

Attach log associated with the bug (can be found in "logs/")
[INFO] Scanning for projects...
[INFO]
[INFO] �[1m-------------------------< �[0;36mcom.mygame:MyGame�[0;1m >--------------------------�[m
[INFO] �[1mBuilding MyGame 0.0.1-SNAPSHOT�[m
[INFO] from pom.xml
[INFO] �[1m--------------------------------[ jar ]---------------------------------�[m
[WARNING] 6 problems were encountered while building the effective model for org.openjfx:javafx-fxml:jar:21.0.1 during dependency collection step for project (use -X to see details)
[INFO]
[INFO] �[1m--- �[0;32mclean:3.2.0:clean�[m �[1m(default-clean)�[m @ �[36mMyGame�[0;1m ---�[m
[INFO] Deleting D:\Repos\MyGame\target
[INFO]
[INFO] �[1m>>> �[0;32mjavafx:0.0.8:run�[m �[1m(default-cli)�[0;1m > �[0;1mprocess-classes�[m @ �[36mMyGame�[0;1m >>>�[m
[INFO]
[INFO] �[1m--- �[0;32mresources:3.3.1:resources�[m �[1m(default-resources)�[m @ �[36mMyGame�[0;1m ---�[m
[INFO] Copying 17 resources from src\main\resources to target\classes
[INFO]
[INFO] �[1m--- �[0;32mcompiler:3.13.0:compile�[m �[1m(default-compile)�[m @ �[36mMyGame�[0;1m ---�[m
[INFO] Recompiling the module because of �[1mchanged source code�[m.
[INFO] Compiling 15 source files with javac [debug release 21 module-path] to target\classes
[INFO]
[INFO] �[1m<<< �[0;32mjavafx:0.0.8:run�[m �[1m(default-cli)�[0;1m < �[0;1mprocess-classes�[m @ �[36mMyGame�[0;1m <<<�[m
[INFO]
[INFO]
[INFO] �[1m--- �[0;32mjavafx:0.0.8:run�[m �[1m(default-cli)�[m @ �[36mMyGame�[0;1m ---�[m
[WARNING] Module name not found in . Module name will be assumed from module-info.java
10:04:04.959 [JavaFX Application Thread] INFO Engine - FXGL-21.1 (27.03.2024 07.52) on WINDOWS (J:21.0.10 FX:21.0.1)
10:04:04.960 [JavaFX Application Thread] INFO Engine - Source code and latest versions at: https://github.com/AlmasB/FXGL
10:04:04.961 [JavaFX Application Thread] INFO Engine - Ask questions and discuss at: https://github.com/AlmasB/FXGL/discussions
10:04:04.961 [JavaFX Application Thread] INFO Engine - Join the FXGL chat at: https://gitter.im/AlmasB/FXGL
10:04:05.951 [FXGL Background Thread 1 ] INFO FXGLApplication - FXGL initialization took: 0.590 sec
10:04:06.129 [FXGL Background Thread 4 ] WARN TMXLevelLoader - TiledMap generated from 1.11.2. Supported version: 1.9.0. Some features may not be parsed fully.
10:04:06.203 [FXGL Background Thread 4 ] WARN TilesetLoader - file:/D:/Repos/MyGame/target/classes/assets/levels/ cannot be loaded
10:04:06.258 [FXGL Background Thread 4 ] WARN TilesetLoader - cannot be loaded using mapURL=file:/D:/Repos/MyGame/target/classes/assets/levels/level_01.tmx
java.lang.IllegalArgumentException: Image dimensions must be positive (w,h > 0)
at javafx.graphics@21.0.1/javafx.scene.image.Image.(Image.java:743)
at javafx.graphics@21.0.1/javafx.scene.image.WritableImage.(WritableImage.java:77)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:143)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:127)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadImage(TilesetLoader.kt:440)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadView(TilesetLoader.kt:156)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:99)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:88)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities$lambda$3(TMXLevelLoader.kt:88)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities(TMXLevelLoader.kt:116)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.load(TMXLevelLoader.kt:58)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.services.FXGLAssetLoaderService.loadLevel(FXGLAssetLoaderService.kt:449)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL$Companion.setLevelFromMap(FXGL.kt:643)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL.setLevelFromMap(FXGL.kt)
at com.mygame@0.0.1-SNAPSHOT/com.mygame.MyGameApp.initGame(MyGameApp.java:89)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.initGame(FXGLApplication.kt:343)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:321)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:313)
at javafx.graphics@21.0.1/javafx.concurrent.Task$TaskCallable.call(Task.java:1399)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)

10:04:06.259 [FXGL Background Thread 4 ] WARN TMXLevelLoader - Parse error
java.lang.IllegalArgumentException: Image dimensions must be positive (w,h > 0)
at javafx.graphics@21.0.1/javafx.scene.image.Image.(Image.java:743)
at javafx.graphics@21.0.1/javafx.scene.image.WritableImage.(WritableImage.java:77)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:143)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:127)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadImage(TilesetLoader.kt:448)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadView(TilesetLoader.kt:156)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:99)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:88)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities$lambda$3(TMXLevelLoader.kt:88)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities(TMXLevelLoader.kt:116)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.load(TMXLevelLoader.kt:58)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.services.FXGLAssetLoaderService.loadLevel(FXGLAssetLoaderService.kt:449)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL$Companion.setLevelFromMap(FXGL.kt:643)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL.setLevelFromMap(FXGL.kt)
at com.mygame@0.0.1-SNAPSHOT/com.mygame.MyGameApp.initGame(MyGameApp.java:89)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.initGame(FXGLApplication.kt:343)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:321)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:313)
at javafx.graphics@21.0.1/javafx.concurrent.Task$TaskCallable.call(Task.java:1399)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)

10:04:06.262 [JavaFX Application Thread] FATAL FXGLApplication - Uncaught Exception:
java.lang.RuntimeException: Initialization failed
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.failed(FXGLApplication.kt:347)
at javafx.graphics@21.0.1/javafx.concurrent.Task.setState(Task.java:710)
at javafx.graphics@21.0.1/javafx.concurrent.Task$TaskCallable.lambda$call$2(Task.java:1429)
at javafx.graphics@21.0.1/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:456)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at javafx.graphics@21.0.1/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:455)
at javafx.graphics@21.0.1/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at javafx.graphics@21.0.1/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics@21.0.1/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:185)
at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: com.almasb.fxgl.entity.level.LevelLoadingException: Image dimensions must be positive (w,h > 0)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.load(TMXLevelLoader.kt:77)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.services.FXGLAssetLoaderService.loadLevel(FXGLAssetLoaderService.kt:449)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL$Companion.setLevelFromMap(FXGL.kt:643)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.dsl.FXGL.setLevelFromMap(FXGL.kt)
at com.mygame@0.0.1-SNAPSHOT/com.mygame.MyGameApp.initGame(MyGameApp.java:89)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.initGame(FXGLApplication.kt:343)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:321)
at com.almasb.fxgl.all@21.1/com.almasb.fxgl.app.FXGLApplication$InitAppTask.call(FXGLApplication.kt:313)
at javafx.graphics@21.0.1/javafx.concurrent.Task$TaskCallable.call(Task.java:1399)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
... 1 more
Caused by: java.lang.IllegalArgumentException: Image dimensions must be positive (w,h > 0)
at javafx.graphics@21.0.1/javafx.scene.image.Image.(Image.java:743)
at javafx.graphics@21.0.1/javafx.scene.image.WritableImage.(WritableImage.java:77)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:143)
at com.almasb.fxgl.core@21.1/com.almasb.fxgl.texture.ImagesKt.resize(Images.kt:127)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadImage(TilesetLoader.kt:448)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TilesetLoader.loadView(TilesetLoader.kt:156)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:99)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader$createTileLayerEntities$1.invoke(TMXLevelLoader.kt:88)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities$lambda$3(TMXLevelLoader.kt:88)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.createTileLayerEntities(TMXLevelLoader.kt:116)
at com.almasb.fxgl.entity@21.1/com.almasb.fxgl.entity.level.tiled.TMXLevelLoader.load(TMXLevelLoader.kt:58)
... 14 more

10:04:06.262 [JavaFX Application Thread] FATAL FXGLApplication - Application will now exit
10:04:06.774 [FXGL Background Thread 2 ] INFO UpdaterService - Your current version: 21.1
10:04:06.774 [FXGL Background Thread 2 ] INFO UpdaterService - Latest stable version: 25
[INFO] �[1m------------------------------------------------------------------------�[m
[INFO] �[1;32mBUILD SUCCESS�[m
[INFO] �[1m------------------------------------------------------------------------�[m
[INFO] Total time: 18.364 s
[INFO] Finished at: 2026-02-08T10:04:18-05:00
[INFO] �[1m------------------------------------------------------------------------�[m

[omicreativedev]

Someone responded

https://discourse.mapeditor.org/t/properties-break-map-in-eclipse-javafx-fxgl/7735

With

_**I’m guessing your tileset is a “Based on Tileset Image” tileset? Looking at your stack trace and the FXGL code, it looks like it’s trying to load an image from the tile, rather than the tileset. It uses tileset.isSpriteSheet in Tileset.kt to determine whether a Tileset is a spritesheet (“Based on Tileset Image”) or not (“Collection of Images”), but isSpritesheet is effectively checking whether the Tileset has any elements - this is incorrect, because s can exist for reasons other than defining the image of a tile, such as holding your custom properties. I imagine adding animations or terrains would also cause this breakage.

This is a bug in FXGL, and you should report it to them. A better check would be whether the Tileset itself has an Image set - if it does, that image should be used, and if it does not, then the Tiles should have images to use.**_

[AlmasB]

Thanks for this. Do you have a minimal example that reproduces the issue that you could upload here? So that it can be used as reference for fixing the bug.

[omicreativedev]

@AlmasB

I've attached what I think might be a minimal example. This is using 21 not 25 but the issue persists even if I go down a version or up a version. It's really tricky, because even if I remove properties from tiles, its glitchy or "hit or miss" depending on what the properties are or where they are.

A friend of mine told me to look through Tileset.kt for something like val isSpriteSheet = tiles.isNotEmpty() and see if it's helps to do something like val isSpriteSheet = image != null?

And I don't really know if the issue is using a sprite sheet, or if using a collection would be better?

Again, I'm such a NEW person to both TileMapEditor and FXGL (and Java). I'm a CS Student, and not very fluent. I could be using the TileMapEditor software wrong to begin with. But I thought it was really straight forward and just a tool to make JSON which should, in theory, be able to manipulated with FX, Java, or whatever library. But it's not playing nicely.

I stripped everything from this .zip. There are 2 maps in the levels folder. The simple map works and renders, but it's useless because nothing has any useful properties. The other map level 01 is just a basic map that crashes.

Another friend said maybe it's the compression? Or maybe 2 problems at once?

I wouldn't mind moving the tile properties to an object layer (for instance, for wall blocking.) But it still crashed even after removing tile properties, I'm assuming because other things have properties too?

Honestly I have no idea how others are getting this work at all.

BlankGame.zip