session_regenerate_id(): Failed to create(read) session ID

[user358]

Hello,

I installed a fresh version of ProcessWire but I can't login to admin panel. How I can fix this issue? (Apache & PHP 7)

Error message after login:

Recoverable Fatal Error: session_regenerate_id(): Failed to create(read) session ID: memcache (path: tcp://172.16.4.160:11211, tcp://172.16.4.212:11211, tcp://172.16.4.213:11211) (line 459 of /home/xxxx/public_html/wire/core/Session.php) 

This error message was shown because Superuser has never logged in. Error has been logged.

[BitPoet]

That line number hints at PW version 2.6 or 2.7. Have you tried with a recent release?

If the error still persists, it's likely a version/configuration problem on your server. PHP 7 is a bit more opinionated about the return values of session handler functions, and older versions of memcache session handlers didn't always return strings where expected. So upgrading the memcache PHP module might help, or switching to regular file sessions in php.ini would be a workaround.