I installed the ramdisk onto a new system, with the intention of storing cache/profile info for firefox onto it so I can quickly load my tabs up (in the thousands range) and avoid using the ssd for this. For the most part it worked, but I noticed after a few hours, any attempts to download files from the portable firefox failed immediately. Even uninstalling the ram disk didn't help, til I did a fresh backup restore from before I installed the software. I have since installed firefox onto a hard disk and have not had any similar issues in the months since.
I am afraid it's pretty hard to re-create this setup and reproduce the bug. Anyway, normally you should only move browser's temporary files (web-page cache) to a RAM Disk, not its executable files or profile settings.