Look at the huge announcement at the top of the forum.
This issue was fixed in the latest commit on github.
Get the latest mouse.simba here:
https://github.com/SRL/SRL-5/blob/ma...re/mouse.simba
You should copy paste the code from your browser into mouse.simba. If you download the file it will have html tags embedded in it that can introduce errors.
You can also download the entire SRL archive by clicking the ZIP button, then you can just copy paste the file from the archive over top of the existing mouse.simba.