Hello! We have a UR20 on my plant and we’ll like to update the software to the mist updated version. Robot been seating in a corner for a year and now we’re ready to use it. It has the Software version 5.14.4 and i tried doing the latest version 5.19 but doesn’t work. Also tried going to the next one 5.14.5 but no luck. Any advice on how to upgrade the software. FYI we haven’t used it much so we don’t remember much about it! Thanks!!
You’re doing the right thing. It should work. What error are you getting? 
Technically you can update from 5.14 to 5.19, as shown in this guide.
What error are you getting? Have you reviewed that your Polyscope image/update is not corrupted? Could it be the firmware in the joints not being updated along with Polyscope?