Has anyone experienced this issue?  This is reported to happen when loading any forum page, but the page shows properly if clicking on refresh/F5.
Forum Problem wrote:
[phpBB Debug] PHP Warning: in file [ROOT]/inc include(includes/arcade/arcade_common.) [fu directory [phpBB Debug] PHP Warning: in file [ROOT]/inc include(includes/arcade/arcade_common.) [fu directory [phpBB Debug] PHP Warning: in file [ROOT]/inc [function.include]: Failed opening 'includes/ar usr/lib/php:/usr/local/lib/php')
 Fatal error: Class 'arcade_admin' not found in /ho functions_user.php on line 3550
If you are seeing this issue, please reply here or PM me with any relevant information, such as when it started (day/time), what if anything happened before this started, etc.  I cannot duplicate the issue, so any information will me help track down (and fix) the cause.
I do believe it is phpBB Arcade related (with the latest upgrade to 1.0RC10).  I will continue to upgrade the forum over the next week or so.  Only 6 more versions to go...
Update: Still happening on Arcade version 1.0.0.  
Further Update:  After much searching, this bug might be fixed in 2.0RC5.  I will get to that version soon.
Thanks! 
~Blue