vrayvrmatmtl2015.dlt failed to initialize

V-Ray V-Ray for 3ds Max Issues
1

Not using 3DsMax that much now-a-days, but today I had to work on a project where I needed to use my good-old 3DsMax 2015.

Starting 3DsMax gives me suddenly the following error:

vrayvrmatmtl2015.dlt failed to initialize (error code -126)

I uninstalled and reinstalled Vray, but the error keeps popping up

Any idea why?

thanks
Menno