After further research, I have concluded this is caused by one of the plugins overriding generator.yaml incorrectly, probably the plugin was not correctly updated to support 2024.3. Investigate which plugin causes this by fully removing them one by one and then report the bug to the author of the offending plugin
This is obviously an MCreator bug, but it looks like you might be able to fix this by locking the code for all your entities and replacing,
with,
Please open a bug report at https://github.com/MCreator/MCreator/issues and attach your workspace. Also let us know if you use any plugins
After further research, I have concluded this is caused by one of the plugins overriding generator.yaml incorrectly, probably the plugin was not correctly updated to support 2024.3. Investigate which plugin causes this by fully removing them one by one and then report the bug to the author of the offending plugin