Hi Max,
These presets are using the 3d_<RENDERER>.mat material library by default located at:
C:\Users\<yourUsername>\AppData\Local\Itoo Software\Forest Pack Pro\matlib
Would you mind to specify this issue more in detail (a screen-shot of the error message would be ideal)?
Thanks in advance for any further comments on this issue you can share with us / our user community.
Best regards,