I've been experiencing lots of crashes. Most of them I'm warned in advance because I get an "Invalid argument" error. Nothing more then that. Nothing more descriptive. Just "Invalid argument". I get it on all levels of certain asm's concerning piping. So much so that those drawings are completely unworkable because as soon as I try to edit them or save them I get the error again but this time followed promptly by a crash.

If I however don't load them lightweight then I don't get that error and I can edit them.

Is this normal ?