In my ftn95 configuration for FTN95 version 8.00 I selected (among others) the following options:
/x64 /check
Then compiling was no longer possible, what is acceptable for me.
Surprising was that I was not able to change my configuration back with ftn95 /config Before the window for selection of options appears an error occurs.
I had to search the ftn95.cfg file and to process the options by editor.