Looks like a bug on that only happens when using redis, thanks for reporting.
Spelling error in Hebrew
When the system sends a new user invitation there is a spelling error, how can I change it?
The translations are at https://www.transifex.com/nodebb/nodebb/, you can fix the errors there.
But I did not find the option of editing strings to translate
You need to create an account and go to the correct language file.