formsbuilder user preferences not saved

Hi, my formsbuilder 12c installation on wondows 10, can't save the preferences i'v set into the cauprefs.ora file.

i'm opening two object library files in formsbuilder, next i load a fmb file and i then compile it.

then i close the formsbuilder, and reopen it.

now the previously loaded object library files are gone.

if i try to set some other preferences i get a frm-10150 exception.

as far as i can see, all the env variables are set correctly, and then correct entries are made in the windows registry.

any idears on what could be the issue???

ragards jan