ayon-core/openpype/hosts/unreal/README.md

Unreal Integration

Supported Unreal Engine version is 4.26+ (mainly because of major Python changes done there).

Project naming

Unreal doesn't support project names starting with non-alphabetic character. So names like 123_myProject are invalid. If Ayon detects such name it automatically prepends letter P to make it valid name, so 123_myProject will become P123_myProject. There is also soft-limit on project name length to be shorter than 20 characters. Longer names will issue warning in Unreal Editor that there might be possible side effects.