Error in class_bbcode.php need help please

[Finger78]

I have been running my site now for a few weeks, have had it setup and untouched the way I want and in use for about a week. It has been working fine for days and now, suddenly my site gives me this error:

Fatal error: Call to undefined function handle_bbcode_item() in /example/example/forums/includes/class_bbcode.php on line 1317

Now, to fix this (at least i thought) I changed styles and out of the about 6 I had to choose from only about 3 worked, well as of last night only 1 is working and the rest (even the vB default style) gives this error.

Now I dont understand why or how the site could be working great for over a week (after all mods etc were in place) and now out of no where its going crazy and breaking the site.

I can access the forums bu typing in the default www.address.com/forums/ but when trying to view it in vBa it doesnt work at all.

I'm unsure what to try and vBa forums offer almost zero technical help (from what I see the forum seems almost untraveled) so I'm hoping someone here can offer some help. I'm not even sure if its really vBa or something else all together...

Please help!