Exception during rest action

Hi

I have seen other people have this error in other places, but does anyone else have an Error pop up when they try and access the Opportunity Marketplace (so you would be an internal candidate) which says "Exception during rest action"?

I seem to get a few and then all quiet for a while and then a little flurry again, but there doesnt seem to be any way to clear the error, I have asked people to clear the cache and use a different web browser but doesnt always work, and you just have to wait a couple of days for it to clear again. Its not everyone just a small minority and I cant see anything that they have in common. Obviously if they are up against a deadline for applications to be submitted this could cause issues