Hi all! 
I tried to register account on http://bugs.tryton.org/ .
I entered “YEKT” as timezone in my account. Which refers to Yekaterinburg Time - Wikipedia . 
When I visited activation link in email, it redirected me to list of issues and also it showed “YEKT” in red rectangle (almost like in attached screenshot) 
when I tried to login, it showed attached screenshot 
 
[Edit: 2021-04-16 10:21 YEKT] Account name is “wyoming”
             
            
               
               
               
            
            
           
          
            
              
                ced  
                (Cédric Krier)
               
              
                  
                    April 16, 2021,  7:31am
                   
                   
              2 
               
             
            
              Here is the report: Issue 2551128: Impossible to validate a user with unknown timezone - Roundup tracker 
I applied the patch on our instance, could you retry activate your account.
PS: the timezone must be entered as path like Asia/Yekaterinburg 
             
            
               
               
               
            
            
           
          
            
            
              
I visited actiavation URL. Nothing changed. Same behavior.
Ok. Should I reregister?
             
            
               
               
               
            
            
           
          
            
              
                ced  
                (Cédric Krier)
               
              
                  
                    April 19, 2021,  7:44am
                   
                   
              4 
               
             
            
              The link has probably expired now. You should try to register again.
             
            
               
               
               
            
            
           
          
            
            
              
Done. Thanks for your help!