Skip Taylor wrote:
In Drupal. Go to Administer/Site Configuration/Performance. The page cache is what was giving me grief.
This sounds plausible. I think the only place in core that this error's wording can come from is a mismatch of form tokens.
Each visitor, during their session on the site, has unique tokens generated from their session data for each form submission. I think it prevents forms being maliciously submitted by bots e.g:
The submission handling checks the token is valid, but if a URL in a module claims to be cache-friendly, yet it actually contains such a token, then one visitor could end up with a cached version generated with another user's token. Hence a token mismatch arises and generates the error message as per includes/form.inc:395
I don't know enough to fix it, but if it can be replicated outside the Resin environment then you might be able to track it down, using two or three separate browsers simultaneously, to a particular form created by a particular module, and then alert the module's owner.
J-P