What the hell is wrong with Dolphin lately?

My site was working fine until last week or so. It was acting up and this error comes up very often. it's like something it works and sometimes it doesn't. Nothing was changed on the host/server side.

Warning: require_once(Thing.php) [function.require-once]: failed to open stream: No such file or directory in /home/crispe/public_html/inc/classes/BxDolMistake.php on line 3

Fatal error: require_once() [function.require]: Failed opening required 'Thing.php' (include_path='') in /home/crispe/public_html/inc/classes/BxDolMistake.php on line 3

Have you checked to see if thing.php is on the server? The error is telling you it can't find the file....

 dolphin 7.1? or 7.1.1?

Dolphin 7.09.

This is a common problem now, other users also have the same problem, error lately. I think it's a systematic error, not a server/host error.  If the file is not there it will not work at all, but it sometimes work sometimes doesn't.

Is the file there? Seems like a simple fix if it isn't there, then add it.

 Yes, the file is there. as I said, it's been working since the day I installed but suddenly this error happened. And it's not just me, other users too.