Consider a board with several installed and enabled styles: users and guests can switch one style to another by adding the argument ?style=XX or &style=XX in the URL (similarly, the admins can add a script to switch to a given style with the same argument, depending the context).

Since phpBB 3.2, the quote tag add two URL (the one to go to the quoted user's profile, the other to go to the quoted post). If you currently use an alternative style (not the default), these URLs become:

• ./memberlist.php?style=XXX&mode=viewprofile&u=YYY instead of ./memberlist.php?style=XXX&mode=viewprofile&u=YYY
• ./viewtopic.php?style=XXX&p=ZZZ#pZZZ instead of ./viewtopic.php?style=XXX&p=ZZZ#pZZZ

Consequently, the first link go to the memberlist (instead of a profile) and the second links go to an unknown post (error message). These two URLs need to be fixed >>> replace the incorrect & by &.