I’m not sure if this problem was Win. 8 specific, but I found the solution under a Win 8 thread on the Paint Tool SAI English boards, and that’s the OS I use for my version of SAI.
So, my first issue occurred while creating brushes by using right click. Every time I right clicked in the brush window, the problem would report an error and close. I hadn’t had a issue with Win XP versions using SAI, but this error occured on both my desktop and mobile (Surface Pro) versions for Win 8.1.
The second issue (as of me writing this) only occurs on the Surface Pro (the first one) with Win 8.1. When trying to draw with the Surface Pro pen, the brush on the canvas would be off-centered from the actual position of the brush on the screen. I searched a few different websites before messing with the settings folder myself and figuring it out.
Both of these problems can be solved with minor edits to the configuration settings in SAI. Open the folder that contains SAI (right click on the desktop icon, select Properties, then from the Properties menu, click Open File Location. In the SAI folder, double-click the file misc.ini.
The 3 sections you’ll need to edit to fix these two issues are:
TabletMouseSimulation = 1
AvoidOldWacomBug = 1
TitleBarMode = 2
Change the values in the file to the aforementioned values, and you should be able to right-click and draw like normal (also, for Surface Pro, if you deactivate the touch screen so that it responds to the pen only, that helps).
Note: My Surface Pro also has the latest Wacom Pen FEEL driver installed. That can be found here.
Posting just in case anyone is going through the same issues ;n; It took a long time to fix… *sniff