Try this...

1. Close ProSeries

2. Run repair updates under the start menu under the ProSeries 2019 folder

3. After that has completed retry

If that doesn't work you can try resetting internet explorer. ProSeries uses ie by default in the background regardless of primary browser. Retry after that's complete.

After that try safe mode with networking. 

Now that rebooting your PC and server if a network setup can be needed to apply certain changes. Hope that helps