I did not talk about RedSDK, that was Dean
I mention Repair and delete the Built-in, i reread and you have re install already so then the Repair option should not need to be done.
The Built-in i for sure would look in to as there may be stuff in there during you earlier problems that could be good to clean out, it will not be cleaned by a re install, and by that you maybe just bring the problem with you in to the new install.
TC should be shut Down when/ if you do it and it will rebuild itself after save a drawing.
You will need to reset your template, cfg (UI) etc.
Normally i would un install and clean out everything about TC 2019 in Document and inside Appdata, minus what you would like to save of course, like drawings etc i.e.
, that i would have moved outside TC first, and then close and done a "Cold" start of pc before reinstall TC 2019
But since it seems to be about a win update it would maybe not help much.
If the rest of your pc run well with the latest win update i dont understand why TC 2019 don't work in win 8 mode.
The other people's that have issues with the built 1809 have not reported back that it did not work.
V20, V21, 2015/ 16/ 17/ 18/ 19 Pro. Platinum
Deluxe 2015/ 16/ 19
Windows 10 Home Premium 64 bit, 32 GB
NVIDIA Geforce GTX 780m, 1 GB