Regarding your question:
The version of .NET required by a particular application, such as Memeo Backup Premium, is determined by the developers of that software. Generally, older applications may require an older version of the .NET Framework to function correctly, especially if they have not been updated to be compatible with newer .NET versions or operating systems like Windows 11. If Memeo Backup Premium v4.6 required an older .NET version on Windows 10, it is likely that the same requirement would persist on Windows 11. However, using an outdated .NET version can sometimes lead to compatibility issues with the operating system or other applications.
If the software causes issues on Windows 11 and the developers have not released an updated version compatible with the newer OS and .NET frameworks, you might need to consider alternatives or contact Memeo support for assistance.