I am having trouble completing polylines– which only applies when I am working on this specific file.
I can click points and draw lines- However, as I come to complete the line by clicking enter or closing the curve, an error icon appears next to my mouse and the line disappears.
I cannot reproduce that error here (but I’m on Windows…).
What does the error icon look like?
Also - and likely the cause of your troubles - you are working in a document with units set to mm and your objects are about 180 km away from the origin. Is the problem still there if you move all to the origin?