I'm having a similar error, with a few exceptions. After installing the latest tubepress pro version it was working fine. The site functions normally, even the pages with my video galleries. However, while I'm adding posts, seemingly at random, I get the Internal Zend Error thrown at me. Here's the full error:
Fatal error: Internal Zend error - Missing class information for in /home/content/18/10066318/html/destinationsmalltown.com/wp-content/plugins/tubepress_pro_4_0_8/src/platform/scripts/boot.php on line 15
It happens when I add Map Locations using MapifyPro. I'm not sure if there's a compatibility issue there or not. I don't think there is, because I was able to use the MapifyPro plugin for a week or more without any of these errors.
Once this seemingly randomly-timed error gets thrown my site goes down. I just have to walk away and after a while things will work.
I have the latest version of WordPress installed and PHP 5.3.
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Update
I attempted to write a php ini for my GoDaddy hosting to disable APC, but the error persists.
I also attempted to update from PHP 5.3 to 5.4 (saw that it helped some people), but the error still persists after the update finished.