Cant Save Encounters in Encounter Builder

Hi, for the last several days (since at least Wednesday the 2nd) encounters in the my encounters encounter builder are not being able to save 

error msg as follows;

We have automatically logged this error giving us a +2 to our Investigation check to help prevent future errors.

In the meantime, you could refresh the page and try building your encounter again. We're sorry for the inconvenience.

*Refreshing does not help by the way

Here's my process from when I was getting that error:

Short version: see if it'll save if you change the party out with one of the presets