I'm curious, where is your PTS folder? If you put it in c:\program files or c:\program files (x86), it might cause problems. More info here: https://systemax.jp/en/sai/. Source: about 1 year ago

I would contact Systemax Software, the maker of SAI. Here's their website: https://systemax.jp/en/sai/. Source: almost 2 years ago

Where did you download it from? If you didn't get it from https://systemax.jp/en/sai/ then it could be sideloaded malware. Source: about 2 years ago

That said, my kid, above all else, had the most fun with paintz.app (website), just creating pictures. He's moved onto brush.ninja now (at 7) and is doing simple gif animations. Source: over 1 year ago

I wasn't sure if that was allowed. The site is brush.ninja, I shall update the original post to show this too. Source: about 2 years ago

Https://brush.ninja/ is fast/nice if you just want to do quick stick figure type animated gifs. Start by drawing something simple in the current frame, then down at the bottom, use the "duplicate" to make the next frame and add some changes. - Source: Hacker News / about 2 years ago

I can suggest brush.ninja for online (2D) animations or OpenToonz/FlipaClip for downloadable software animations, along with Blender for 3D animations (all of these are free to download and use). Source: over 2 years ago