Tephea

I was unable to use noVNC in Firefox for the better part of a few months, when it worked fine in Chrome. Clearing cache did not work, but going into my browser history (Ctrl+H) and finding my Unraid IP, then selecting "Forget about this site..." worked for me.

This was extremely helpful. I recently had a slowly dying cache drive containing my Home Assistant VM. My "backups" were contained within the VM rather than pulled anywhere else, which in hindsight was as good as no backup. I was able to navigate into the backups and pull them out by following your instructions. I tried Mat W's solution above but with my corrupted cache I can't currently install any VM's and haven't dug for a solution yet.