Ugh, can't find tcp, what did my web hosting people change?

Permalink 1 user found helpful
New error message when I try to access my cvtg.org web site which I haven't touched for a while:
is_dir(): Unable to find the wrapper "tcp" - did you forget to enable it when you configured PHP?
Anyone see this happen before?
The site is hosted by surshothosting.net

 
cvtgorg replied on at Permalink Reply
The owner of sureshothosting.net says:
Over the weekend our datacenter detected a critical error on the network segment housing the server your account is on and proceeded to clone the server to a different network segment. While it is an exact clone, it is possible that something is slightly different in the hardware that may be behind this.

I saw something while googling about somebody getting the same error message with another CMS and needing to change a hard-coded IP address somewhere but I don't know where to look in Concrete5.
Gondwana replied on at Permalink Reply
Gondwana
It could be a php extension.
cvtgorg replied on at Permalink Reply
The very helpful manager of sureshothosting said (and it's mostly Greek to me):
"I found that the issue was caused by a switch, in the recent cPanel PHP update, to using Redis as the default session storage engine. This appears to be a known issue with Concrete5 and Redis. The solution I found, and implemented, was to modify the Concrete configuration file located at "/concrete/config/concrete.php" and change the "session.save_handler" value to 'database' (the default value is 'file' but the "session.save_path" value is empty). I made this change and the site now loads."
That site was on Concrete 8.4.3. I have another site on version 8.1.0, valleygospelchoir.org , that seems to still be hung even after making a similar change. I'll try to upgrade that one later.
cvtgorg replied on at Permalink Reply
New error message when I try to log in an edit pages:
preg_match(): Compilation failed: invalid range in character class at offset 4
Somewhere in the code there must have been a regular expression with an invalid range, an example online said it could be something like _-\s (somebody has a hyphen where they maybe meant \- ?) Older version of PHP must have ignored it, but newer version makes the site crash.

I ended up unzipping the latest version of Concrete5 to my sites, only replacing the concrete/ directory at the top level and still making the concrete.php config change (even though I saw something in there now about Redis). I am back online now. (I couldn't use the automatic updater since my site was really broken, but I don't like it anyway, it leaves too many files around and I'm trying to keep my footprint as small as possible.)