I'm having a persistent problem with login on a site running 2.4.10. The site had run reliably for over a year when this problem suddenly arose about a week ago. I've checked with my hosting provider, and they claim to have made no changes. here are the symptoms and the steps I've taken so far:
Initially, the client reported the home page was not displaying correctly. I quickly isolated the issue: on the home page (only) the <% base_tag %> control was emitting the file name on the end of the url, so all links were pointing to xxx.com/index.php. This was causing problems loading some assets and causing links to fail. I fixed this with Director::setBaseURL() in _config.php
Immediately after, we noticed that when going to /admin, after entering credentials the first time, you are directed back to the login form again. removing the call to setBaseURL() did not fix this. I have noticed that setting the persistent authent ("remember me checkbox") DOES give me a "You're already logged in as [admin], Log in as someone else" screen instead of directing me back to the login. I'm not, however, able to reach the admin at all.
The client is hosted on GoDaddy. I have double checked phpinfo() and verified the following settings (in php5.ini):
asp_tags = Off
magic_quotes_gpc = Off
magic_quotes_runtime = Off
I've also verified disk usage: I'm only using 192MB of 100GB, so disk space does not seem to be an issue.
I've also put the site in dev mode in order to run a build. that did result in an error after the database built - Fatal error: spl_autoload() [<a href='function.spl-autoload'>function.spl-autoload</a>]: Class DebugView could not be loaded in /sapphire/dev/Debug.php on line 362. This error persisted on the site while I was in dev mode. I came across a report of a similiar issue (with SS_log instead) that was resolved by adding session_save_path(getTempFolder()); to _config.php. This got rid of the error for me as well. There were no changes to the login issue after the build.
Any assistance, hints, or pointers to references would be greatly appreciated. Thank you in advance.