[Help] NeoForge 1.21.1 ecxception because of Mixin Config file

For some odd reasons NeoForge 1.21.1 on MCreator 2025.3.45720 throws a exception about a mixin config file missing.

Check this link for details:
https://mclo.gs/lgKOuy8

I know how to fix this but why does NeoForge 1.21.1 create a mixin configuration in "neoforge.mods.toml" but does not create a mixins file?

Maybe it didn't create it as the first time creating the workspace was an error and tried again. After the second time it worked but it could lead to fail the creation of the mixins config file.