A bunch of exceptions as shown below, and then finishing off with:
[23:00:13] [FTB Backups backup thread 0/INFO]: Backup size 299.5MB World Size 433.2MB

The backups seem to create though and my server hasn't crashed recently. These exceptions are annoying because they create very large log files.

For reference, I am using Better MC Fabric 1.19.2 v11

[22:30:00] [FTB Backups backup thread 0/INFO]: Rendering region file -1 0
[22:30:00] [FTB Backups backup thread 0/WARN]: Failed to render chunk (25, 11) section 4. This is very likely because your chunk is corrupt. If possible, please verify it manually before sending a bug report.
java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because the return value of "java.util.Map.get(Object)" is null
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.BlockState.getProperty(BlockState.java:23) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer.parseBlockState(ChunkRenderer.java:33) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.lambda$renderSection$11(ChunkRenderer_1_18.java:306) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.color.BlockColorMap$StateColors.getColor(BlockColorMap.java:176) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.color.BlockColorMap.getBlockColor(BlockColorMap.java:294) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.lambda$renderSection$12(ChunkRenderer_1_18.java:304) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[?:?]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[?:?]
at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) ~[?:?]
at java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[?:?]
at java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:411) ~[?:?]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921) ~[?:?]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682) ~[?:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.renderSection(ChunkRenderer_1_18.java:307) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.renderChunk(ChunkRenderer_1_18.java:191) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.RegionRenderer.renderRaw(RegionRenderer.java:149) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.RegionRenderer.render(RegionRenderer.java:61) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.world.RegionFolder$WorldRegionFolder.render(RegionFolder.java:179) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.world.RegionFolder$CachedRegionFolder.render(RegionFolder.java:467) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.BackupHandler.createPreview(BackupHandler.java:145) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.BackupHandler.lambda$createBackup$4(BackupHandler.java:250) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804) [?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?]
at java.lang.Thread.run(Thread.java:833) [?:?]
[22:30:00] [FTB Backups backup thread 0/WARN]: Failed to render chunk (26, 10) section 4. This is very likely because your chunk is corrupt. If possible, please verify it manually before sending a bug report.
java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because the return value of "java.util.Map.get(Object)" is null
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.BlockState.getProperty(BlockState.java:23) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer.parseBlockState(ChunkRenderer.java:33) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.lambda$renderSection$11(ChunkRenderer_1_18.java:306) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.color.BlockColorMap$StateColors.getColor(BlockColorMap.java:176) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.color.BlockColorMap.getBlockColor(BlockColorMap.java:294) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.lambda$renderSection$12(ChunkRenderer_1_18.java:304) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[?:?]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[?:?]
at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) ~[?:?]
at java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[?:?]
at java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:411) ~[?:?]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921) ~[?:?]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682) ~[?:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.renderSection(ChunkRenderer_1_18.java:307) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.ChunkRenderer_1_18.renderChunk(ChunkRenderer_1_18.java:191) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.RegionRenderer.renderRaw(RegionRenderer.java:149) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.renderer.RegionRenderer.render(RegionRenderer.java:61) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.world.RegionFolder$WorldRegionFolder.render(RegionFolder.java:179) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.de.piegames.blockmap.world.RegionFolder$CachedRegionFolder.render(RegionFolder.java:467) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.BackupHandler.createPreview(BackupHandler.java:145) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at net.creeperhost.ftbbackups.BackupHandler.lambda$createBackup$4(BackupHandler.java:250) ~[ftbbackups2-fabric-1.19.2-1.0.17.jar:?]
at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804) [?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?]
at java.lang.Thread.run(Thread.java:833) [?:?]

It looks like there is a corrupted chunk in your world causing our image preview to throw and exception

Same as #42

Fixed in latest release

Problem still occurs in the latest FTB backup release.