Can't import knxproj file from ETS 6.1 and 6.2

I had imported an older knxproj file in August 2023 from ETS 6.1.5686.0. Today i wanted to import an newer version from ETS 6.2 to Home Assistant 2024.4.1 and got an error message that the file is to large (1,5 MB). I tried to reload the older one from last year and got the same error message (1,4 MB). Perhaps something broken in the import modul.