Wrong mod loader

3 errors

A Forge jar in a Fabric instance, or the other way round. The file names look the same.

Wrong mod loaderAccessWidenerFormatException: Namespace (named) does not match current runtime namespace (intermediary)Check the crash log for the line 'Failed to read accessWidener file from mod <modname>' to identify the brokenWrong mod loaderFabric mod dropped into a Forge or NeoForge instanceA Fabric jar has fabric.mod.json; Forge/NeoForge want META-INF/mods.tomlWrong mod loaderForge mod dropped into a Fabric instance (and the other way round)Forge and Fabric jars are not interchangeable — the file names often look identical