Fatal error: input in flex scanner failed

What is a flex scanner

[quasi]

I have a website built on a home server that I've been testing. Today I was hitting it from work with no problem then I got this error:
"Fatal error: input in flex scanner failed"
I also cannot see any of my images, backgrounds etc., and I'm also getting the:
=========================
"Forbidden

You don't have permission to access foo.php on this server.

Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request."
==========================
error.

What could spontaniosly cause this?

[zCat]

"Flex" is one of the utilities many programming languages use in parsing, e.g. translating source code into something the computer can understand. Evidently PHP is having some serious problems parsing some code which are causing relatively low level errors. Given the other problems you describe it sounds like there's some deeper problem with your system (disk full, or hardware problems such as bad sectors on the hard disk or bad ram are corrupting some data, or maybe it's just hopelessly overloaded).

I'm just guessing though, I may be wrong.

[quasi]

It looks like I had some system failure but did not completely crash. I could telnet to the box but could not run any commands. Shutdown the box and the login screen came up with field lables in Dutch or something, strange. Fedora core 1 by the way. Changed the DISPLAYMANAGER to default and the language issue was fixed. Then just decided to go to runlevel 3. I'll see how that goes. Been having a little trouble with the stability of this system. Hard drive and system install less than a week old. Previous system was identical and had no problems.
Thanks for the reply. You were right obviously some system failure.

[zCat]

Pleasure :-). I hope you can sort the problems out.

I'm sort of gratified my guess was in the right direction; though I'm not a professional sysadmin I've been messing around with web servers for long enough to gain a certain feeling for different type of error, and that was one of a sort which would have me on the telephone calling someone with physical access to the box in question.

BTW I'd avoid using telnet if you can, and stick to SSH.