Thank you for the feedback! Strangely enough, I've been using profiles since porting this addon, and I'm still able to create and duplicate profiles in Firefox 89 without any problems. Could you maybe get in touch with me to investigate this bug? Perhaps it's a bug that only triggers under specific circumstances (for example only on certain Operating Systems or Firefox versions). You can either file a bug report on https://github.com/bertvandepoel/sabconnectplusplus/issues or if you're not comfortable with GitHub you can send me an email. Thank you for your feedback and I hope we can get in touch soon to try and fix this bug!