I'm having a problem with my map, I went through and first had 6 breakables then I went and had a total of 10, everything blew up fine and dandy. Now that I have 13 anytime I try to blow up the 4 new ones I get this "fatal error" :

SZ_getspace: overflow without FSB_ALLOWOVERFLOW set on Server Spectator Buffer

It shuts down HL as soon as the rocket hits the func_breakable, now I can still blow up my older ones just fine with no trouble, but just these 3 whenever I try to it just blow them up same problem everytry.

So does it mean I have too many func_breakables or what?

sz_getspace is a lack of memory crash
could be caused by a few things, but i would check your new breakables, have you directed the gib model to a misnamed model?
or possibly the breakables are so big that its making too many gib models at one time, or is one triggering itself? each other?

if it crashes every time you blow up a certain object, then that is your problem {the object} check its properties carefully

Yep, it was the gibs, it was set to glass, its quite a big break so that was a lot of shards.

13 isnt the max amount, trust me ;), there is something wrong with one of the breakables, if u cant find the fault, delete them, compile to make sure it works, and make them again.