I have just had the same problem! I wanted to do the test 'Dutch to English Translation Skills' (https://www.upwork.com/ab/tests/test/819) but it states I already did the test and cannot do it again until 11/5/17. I definitely didn't take it yet though! Much appreciated if you could help me too.
Welcome to upwork! I checked and your still in the process of completing your profile. Please complete it and get it approved, go through the guides, tutorials, courses, videos, Help articles and Community discussions compiled in the following thread, designed to help new users get started on Upwork.
Afterwards, if you have any questions feel free to follow up in the Community and we'll gladly help you with them.
I have had the same problem... Yesterday I was doing a test namely "English To Dutch Translation Skills Test". Not even halfway through the test I lost internet connection which left me unable to finish the test. Unfortunately, I can't seem to be able to resume the test, nor take it again or have a score. I would very much like to restart the test or resume it to get a score since ths is one of my major skills to get hired.