Temporal solution for the "Session expired or cookies are not enabled in your browser" registration cache error.

I had the same problem on user registration showing the expired session message if the explorer was closed with a not completed registration. I tried EVERYTHING, disabling any single plugin to see if was causing the problem, change config, ordering plugins, etc etc etc. I have not found the cause of the error, and based on my investigation this error has multiple causes, making me suspect that is maybe a CB error or weakness. Some users having this problem got it solved upgrading cb or disabling some third party plugins, in my case that was not working.

After more than 12 hours of research the best solution I found was install the free plugin JOTCACHE and using their EXCLUDE URL funtion to make comprofiler not cacheable. That solved my problem and allow me to have my site cached. I don´t know what is the impact of not having comprofiler cached, but of course for now its best than having my site with cache disabled.

Now you know , if you have that problem and you cant find a solution, just do this:

1-Download JOTCACHE and install.
2-Disable the default joomla Cache plugin.
3-Enale the JotCache plugin.
4- Go the de JOTCACHE component configuration, go to EXCLUDE URL, mark comprofiler and SAVE.
5-Clear cache.Now the registration will work and you will have a big part of your site cached.

Also that plugin has a very nice score and is a nice upgrade from the basic joomla cache plugin with tons of options and extras.

I am sharing this partial solution to help the users having this cache issue to fix the registration problem and don´t lose more new suscribers while a definitive solution is found.

Ensure you're using latest CB 2.x release (recommended Nightly) installed. Then ensure CBs system plugin within Extensions > Plugin Manager is ordered first. CB will then purge its own page cache to avoid CB from being page cached, which avoids the issue you're experiencing.

Caching issues in CB are typically strictly caused by Joomla page caching (which is disabled by default). 3rd party caching could also be the culprit if it uses a different caching file structure than Joomlas page caching and is equally as aggressive.

I have tried everything including your suggestions and the problem is not gone, I had to use that selective cache method while some update fix it or I find the cause of the problem. Thanks!

Are you using page cache when the issue is present for you? If so does disabling page cache solve your issue? If paging caching is not enabled then you may have something else installed doing caching as core Joomla caching does not cache every page by default (only page cache does) and only caches Joomla content articles and modules.