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