Transferred logins don't show up
I transferred all files, including key3.db and logins.json to a new computer. Everything looks just like it did on the old one, except the saved logins are missing. The Exceptions-Saved Logins is filled with the previous data, but no Saved Logins.
This process worked fine on another such transfer I recently did.
Firefox 55.0 (64bit) on Win10 Pro (64bit)
Problems have been reported with v55. I called for more help.