SquirrelMail 1.4.22 PHP 5.6.36-1 1 PHP warning during login: PHP Warning: Illegal string offset '' in /var/www/ee/functions/imap_general.php on line 708, referer: https://webmail.oo.net/src/login.php No PHP warnings or errors after that.
I just did a quick test on the latest version of Xubuntu (18.04). Firefox and Surf-2 work fine. The problem persists with Epiphany (Gnome "Web" browser) and MiniBrowser (I accidentally listed MiniBrowser as working in the original report). Do other browsers matter or is it sufficient to observe the problem in Epiphany?
What is happening when you try to reproduce? Steps taken. Using Epiphany Browser (Web), log into SquirrelMail account. Then click to open a message. Operation fails with notice to log in. Using latest updates of Xubuntu 17.10 from Ubuntu repository with Epiphany 3.26.1, WebKit+ 2.18.0, and SquirrelMail 1.4.22
Squirrelmail loses login with several browsers, not others