Problem solved. Our host confirmed they added new firewall rules which caused the problem. The rules has been removed and now it's working again! Sorry for the trouble @Claude_Schlesser Thank you for your excellent support!
Thx for your reply @Claude_Schlesser We are on a hosted server so don't know if the hosting company made any changes. The "Warning! Your users cannot login." email from support@oneall.com came on Saturday the 25th. I'm almost sure the hosting compan…
Thank's for your reply Claude. Your code did not work like expected so did a little googling and found out that the wp_redirect function require a exit(); so after adding this code after wp_redirect ('https://hamar-tennis.no/wp-login.php?action=reg…