Getting this error repeatedly in cron runs with almost all aspects of the plug in disabled -- only page caching operating (even with page priming disabled):
Fatal error: Call to undefined function w3_url_format() in myrootpath/wp-content/plugins/w3-total-cache/lib/W3/Plugin/PgCacheAdmin.php on line 213
Also experienced complete crash of site after getting this error email:
Unfortunately an error occurred while creating the minify cache. Please check your settings to ensure your site is working as intended.
All screens on the site were only showing white and I had to a full uninstall and reinstall to get back in. I have not dared attempt to reactivate the minify settings.
Additionally, I developed a bad feeling about the user settings interface, I was trying to understand what the object life time for pages is in configuring the page cache and found in the forums that it is set under the browser cache setting -- not crystal clear where. This further diminished my confidence in the accuracy of the user settings interface and therefore in the basic integrity of the application.
Finally, and this is not a wordpress core incompatibility, but it is a problem for me, it does not work properly with BBPress. Again with only the page caching enabled, it is not refreshing pages when people add replies to a BBPress Topics.
So, I'm afraid it's an unintall for me.