Problem after Update to Cubase Pro 8.5


I used to work with Cubase Artist 8 so far and yesterday updated/upgraded to Cubase Pro 8.5

Installation worked fine without any issues so far.

But when i load my current Cubase Project in 8.5 Pro which i worked on the last weeks in Cubase Artist 8, some Audio files / presets for some VST Instruments cannot be loaded although i use the same folder for the Cubase Projects in Pro 8.5 as i used in Artist 8. I just cannot understand this behaviour since the missing files are located in this folder. But Cubase 8.5 Pro is not able to find them.

Is this a bug or are i missing something?

Would be glad if someone can help me!

Thank you very much,