We have a client who applied the GP 18.3.1200 service pack to a W7 workstation running GP 18.3.1173. As soon as they try to open any window in GP, GP crashes. In the event viewer you will see a .Net FW fatal exception and a reference to CTPWIN32.dll. The really bizarre thing about this is that it only crashes in one company. I have tried to uninstall GP and re-install and that did not help. I did notice in the DU0000020 that prod ID 6499 never got upgraded. I do not think product is used any more. All other workstations are W10. Is W7 the problem here? Is there a fix for this?