I seem to have found a fairly easy fix for this.
!!BACKUP YOUR SAVE FILE!!
Using notepad++,
open your save file in,
C:\Users\*you*\AppData\Roaming\Strive for Power 2\saves
find the line containing the job that is stuck, (the header for this line is "active_tasks")
EX:
{"code":"farming_veges","messages":[],"mod":"mod_farm","product":"vegetables","progress":0,"task_location":"aliron","threshold":0.233333,
"workers":["hid914211918"],"workers_count":1}]
Edit the lines,
"workers":["hid914211918"],"workers_count":1}]
So they look like,
"workers":[],"workers_count":0}]
Save the file and check to see it worked.
Haven't tried this with other jobs but I imagine it would work with any issues like this, just be sure the task_location matches the job you're trying to fix.
Hope this helps
Perhaps we'll see an update soon???