Hi Pete,
Sorry it took me so long to provide you with the information you need. First I had to sort things out here at home before I got back to the sim. My apologies again.
After reading the other comments, I've been cleaning up the registry clutter.
This did not go smoothly and took quite some time. Fortunately, it did improve because a number of errors were fixed.
Info about my system:
I did a clean install of Windows 10 and then installed P3d 4.5 and FSUIPC.
The hardware I use consists of; Saitek Yoke, USB throttle and rudder pedal. I also use five USB PoKeys cards to operate various push buttons and switches. I have these PoKeys, by means of given the software, a name and PID to better identify them.
Glareshield - AP1; PID = 1002
Glareshield - AP2; PID = 1003
Pedestal; PID = 1004
Service panel; PID = 1005
CptSidePanel; PID = 1006
All cards are recognized by windows. P3d also recognizes the cards and shows them in the menu 'options \ controls'. Here I can also assign buttons to certain functions except for the 'Service panel' card. This card is recognized, but no buttons can be assigned. This also applies to assigning buttons in FSUIPC. (I get that, because if it doesn't work in P3d, it doesn't work in FSUIPC either, right?)
I hope I have given you enough information with this. If this is not the case, I would like to send you more.
As a thank you for your commitment and help with this annoying problem. I really appreciate this!
FSUIPC5.1.log
FSUIPC5.ini
FSUIPC5.JoyScan.csv
FSUIPC5.log