Problem looks just like with every VST loading problem.

Steps to reproduce:

1. Download any VST plugin into a directory, in which path there are diacritical marks (in Polish we have these: ąćęłńóśżź), for example C:/Users/Jacek Mariański/VST/plugin.dll
2. Try to load them.

Easily fixable by moving into any other folder. Like to C:/VST/