Blank CiviCRM - "unable to read resource" errors

[jsimonis]

Occasionally our CiviCRM just goes blank. We've had this happen on our live site (which runs 4.3.1) and our development site (which runs 4.4.4). We'll get the following two errors in our Drupal report:

User warning: Smarty error: unable to read resource: "CRM/common/jquery.files.tpl" in Smarty->trigger_error() (line 1094 of /home/sandbox/public_html/sites/all/modules/civicrm/packages/Smarty/Smarty.class.php).

User warning: Smarty error: unable to read resource: "CRM/common/drupal.tpl" in Smarty->trigger_error() (line 1094 of /home/sandbox/public_html/sites/all/modules/civicrm/packages/Smarty/Smarty.class.php).

And now a new one has started showing up instead of the drupal.tpl file:

User warning: Smarty error: unable to read resource: "CRM/common/fatal.tpl" in Smarty->trigger_error() (line 1094 of /home/sandbox/public_html/sites/all/modules/civicrm/packages/Smarty/Smarty.class.php).

The files are all there with the same permissions as everything else in the folder (644).

I've tried replacing the files. Deleting the templates_c folder and letting it regenerate. Clearing the CiviCRM cache from the database. Sometimes this works to get everything working again. Sometimes it doesn't.

I had in the past only had this happen with my 4.3.1 install, but it just started doing it with the 4.4.4 install.

What could possibly be causing this? It's getting pretty frustrating to have the entirety of CiviCRM go down. I'm having to keep an alert on for our live site so that it tells me if our event registration pages go offline so that I can hurry up and fix it before it affects too many people. I've tried getting help in IRC, but can never seem to catch anyone around. I would greatly appreciate any help you can give. 

[clarkac]

Could this be some caching/performance software like eAccelerator or xCache?  These have caused similar problems - but usually worse than you describe.  Worth a check though.

[jsimonis]

If these are things we have to turn on, then we're not using them.

[clarkac]

No, sorry, didn't make myself clear.  These are things that can screw up Civi, that maybe your host is running that you might not be aware of.  Worth checking with them.

[jsimonis]

Gotcha - that's why I needed to know if it was something I would install. I have another server with this host that has never had these issues. But maybe something is going on for this server that isn't on mine.

[jsimonis]

Nothing I've been able to find is different on this server instance than the other I have with this company. But it keeps happening - CiviCRM just went blank again with messages about not being able to read those files:

User warning: Smarty error: unable to read resource: "CRM/common/drupal.tpl" in Smarty->trigger_error() (line 1093 of /home/username/public_html/sites/all/modules/civicrm/packages/Smarty/Smarty.class.php).

User warning: Smarty error: unable to read resource: "CRM/common/jquery.files.tpl" in Smarty->trigger_error() (line 1093 of /home/username/public_html/sites/all/modules/civicrm/packages/Smarty/Smarty.class.php).

We're also getting this error:

Notice: Undefined property: CRM_Core_Config::$useIDS in CRM_Core_Invoke::init() (line 122 of /home/username/public_html/sites/all/modules/civicrm/CRM/Core/Invoke.php).

It was fine just a little while ago and now it's giving the blank screen.

[jsimonis]

Ok, I've found out some more about our issue.

We have a server with two accounts set up on it - one is the live site and one is the development site. The development one is a copy of the live site, except that is where we are testing upgrades, new page setups, etc.

For some reason the two CiviCRM installs are conflicting and that is what is causing our blank screen problem. If one site is working, the other is blank. If I run the link to clear the link on the blank site to clear the cache (/index.php?q=civicrm/menu/rebuild&reset=1), that site begins working again and the other goes blank. We then get a bunch of pop-up messages on the working site that it can't find certain resources and the addresses it lists are all wrong (for instance, on the live site it'll say /home/sandbox/public_html/... when it should say /home/live/public_html/...).

Both sites are using different databases and different codebases. The civicrm settings files are correct and points to the right places. I've done a search of the mysql databases and neither reference any files or anything that doesn't belong to them. The templates_c folder has been removed and allowed to recreate, etc. I can't find anything that should have the one site looking at the other, but that is exactly what happens.

I've had the techs on our server looking into it and they're at a loss as to what could be causing it and suggested I ask here for any areas they could look, pointers, etc.

[jsimonis]

Ok, I've had our web host looking at it for a while now. At this point it appears memcache might be the culprit. As soon as turned that off, both sites loaded up. Now to keep watching them to make sure everything is ok.

[Tony Horrocks]

Hmm. What I did was to remove the existing civicrm templates files in sites/default/files/civicrm

Seemed to do the trick

[jsimonis]

Yea, we cleared those again and again without any luck. Nothing changed until we turned off memcache. Then everything works. Haven't had the problem since.