Tokens keep 'disappearing', drush rr fixes the website for a time, sometimes hours sometimes seconds As title suggests my problem is missing tokens, at random intervals tokens will just cease to work on the site in question which makes any webform entries that are emailed out to a client appear empty. It also gets rid of all metatags from pages. 

Metatag shows this while broken:


Then if I catch it in a good mood after running drush rr:


I am unable to see any errors in the database logs, no warnings/notices around the time of this happening either. Haven't got Entity Tokens enabled. The behaviour seems entirely random. I have read en earlier question with similar problems being caused by Node Export, I do not have this installed either.

Latest Drupal Core, latest Metatag, latest Webform versions. Infact everything is latest version as I ran a bunch of updates hoping that would fix the ongoing issue. 

The URL Alias Patterns page is also empty, regardless of whether I have run drush rr and appeased the bug.

SimpleTest run on Token results in 0 fails 0 exceptions and a few debug messages that don't seem relevant.

Webform seems to be the culprit here, as it happens more often when I'm submitting webforms, though I'm not sure if it is. Version 4.1 of Webform.

Any help/ideas greatly appreciated
We've run into this problem as well on a shared hosting production environment, as well as our staging environment. The first on PHP 5.5.9 with Zend OPcache v7.0.3, the latter with PHP 7.0.22 with Zend OPcache v7.0.22. In both environments some site un-deterministically "forgets" tokens. I debugged this down to function_exists() in the implementation of the hook system of Drupal. It seemed PHP just forget that modules implement the hook_info() functions. 

A restart of PHP (PHP-FPM in these cases) fixes the problems, so my best guess is that the Zend OPcache is responsible for this erratic behavior. Note that the fact that environments are shared will probably increase the odds of this bug to surface.