I have a multi-company setup, with US localization installed for the Parent company and 1/4 child companies.
I want to active Chart of Accounts for other 3 companies. However, when I switch to one of them and try to choose Package in Invoicing Settings, I get an error: You cannot have two users with the same login!
Exploring code showed that this error is triggered by website module.
In order to fix my issue, I uninstalled the website module, installed Fiscal Localization, and installed it back again.
Hope it may be useful for those who face the same issue.
I wonder if I can report this kind of module compatibility issue somewhere?