Hi folks,
I also ran into this same issue recently and was happy to find the explanation here (thanks to all you knowledgeable people who share your experiences and provide so much help to the rest of us). Just in case this may help other technically-challenged users like myself, the problem was I had a "&" character in the share name. Editing (via unraid web) the name and removing the offending character solved the problem. Acceptable characters as declared in the wiki are "a-z, A-Z, 0-9, - (dash), and . (dot)".
So as it stands the system allows one to create a share name with non-allowed characters - and it works fines seemingly except for the Compute.
Also noticed when editing share name to correct the problem, that when the change was applied I got the message saying the old share name was "deleted" - it would be less alarming if it says "renamed" :-)
(I am not an experienced poster or forum user so apologies in advance if I have inadvertently breeched forum etiquette in replying to this old message).