Cannot convert µVision .uvprojx to Keil Studio .csolution.yml

Hi

I'm evaluating MDK v6 because I cannot buy a new MDK5 license. And I have a lot of questions. Here is my first question:

When I try to convert any of my MDK5-µVision project files, I always get this error:

0 out of 1 target(s) converted
Error: 1 error(s), 0 warning(s):
Errors:
The target "K64F120M (Flash)"error when trying to convert absolute path to relative one

This is the output when trying Project->Export in µVision 5.41. When I try it with the "Convert a µVision Project" from Keil Studio in the CMSIS-View, I get a similar message in the uv2csolution.log. uv2csolution.exe is version 1.5.0.

By the way: What is your opinion about switching from MDK 5 to MDK 6? Is is it too early? Or does it make sense at all?

Thanks and best Regards
Reto