I have done a factory reset on my phone. I keep getting the join HTC Club notification but if I try to follow up on it I get "Please update HTC Account to continue use [sic] this application". If I go to "Account & Sync" to try to add an HTC Account, I get the same message. Any idea what is going on, please?
Open "Play Store" and search for "HTC account". You will find an App called "HTC Service-HTC Account". Click on updat. Afterwards you can login normally using HTC Account in Settings-> Accounts & sync.