Extensions - Export - Pre-Process File Save As

I am not sure if this is related to #49 (closed) , but I think this is something different so I am opening this as a new issue.

There seems to be something wrong when using the Pre-Process Save faile As . I am using 1.0 (1.0+r73+1) and I have have used this extension before without issues, but today I tried it again on a fresh install and it is no longer working. As far as I remember, it would open up a window to set up plot speed, rotation, pen number etc and on apply would ask where the file should be saved. Now It flashes a "working please wait" for a short moment and then closes the window without doing anything. This has been tested on Ubuntu 18.04 , 20.04, and confirmed on macOs High Seiera