Problems with ODATA feeds - invalid credentials

I have a set up of data that updates  2 times a day automatically, the source of the data is all via ODATA. 

I've never had any problems with this before and nothing has been changed. The data does seem to be occasionally updating successfully still, but I am unable to manually refresh it and sometimes to automatic updates are failing.

These are the errors that I am seeing - 

If I try to update credentials I just get the following - 

Anyone any ideas - this has been running automatically for around a year with no problems and no changes have been made?

Thanks.