@שמח-לעזור could you translate that error into English?
Are you hosting it yourself or paying someone else to host?
Do you have cmdline access?
Did you just install NodeBB, or did this happen as a result of a plugin?
For my original problem, I think I found a bug.
For some reason the user password length was set to 0 (I didn't set it that way, it's not possible). When I set up my forum, my password was 7 characters long (before launching the site, I change the password to a complex and unique one, but during the development process I use a simple one that I remember). When I transferred the forum to the server and edited Users -> Settings, I set the minimum password to 8 characters, because it was impossible to leave the field with a default value of 0. And here I see a bug, because no one expects this behavior. Once the minimum password is set, NodeBB simply stops accepting any passwords that are shorter. This is completely non-obvious and as an admin I fell into a trap. I would expect two behaviors:
Continue to accept set passwords even of shorter length until a password change is required
Display a warning and reset passwords of shorter length if the administrator confirms this action.
If you are seeing [object Promise] in your output it could be due to a missing await or returning a promise instead of the html string. You didn't post the surrounding function this code is in or which plugin hook it is using so can't really tell what is causing it.