Building up quite a few posts here for you to look at and comment on. If somehow AES Crypt is giving you trouble, there’s also SharpAESCrypt.exe in the Duplicati folder, but it’s a command-line tool so more work.
Here is its help text, and there’s another post there citing a case where GUI restore failed, but CLI worked. Keeping on original path might be best. CLI syntax is somewhat complicated to get right in complete form. Examining things in more detail would probably best be done after the immediate emergency calms down.