Unable to save custom vehicles

When I try to save a customized vehicle, many times it will not let me type a filename. I can click in the field/box and a cursor appears, but when I type nothing appears. It seems the keyboard is in game-control mode, because if I hit the "h" key, the horn honks.
This doesn't happen every time, but I have only been able to save a customized vehicle twice out of several dozen times trying.
Any suggestions? Thanks.

 

Yes, the cursor is in the input box and it's blinking, but when I type nothing appears. In fact if I hit the H key the horn honks. So it appears to still be in game-control mode rather than letting me type anything.

 

Disable mods, then clear cache, try to disable the option <allow forcefeedback when window is not focused> It may be that you have bindings of the keyboard in the FFB section. If that doesn't work then it will need to be fixed by the devs.