Since that little update the other day I've lost my audio. Getting a error message instead- Sound Error (play:b-2147221164) any ideas?

Just to clarify some things, to help find the cause / debug:
- what kind of little update do you mean? There was test patch 0.7E12 released recently, is that it?
- did you have version 0.7E installed before, on top of which you installed 0.7E12 test patch? If not, what version were you on (last time it worked), and what version are you currently on (without sound)? Check version at the bottom of main menu.

Quote from MandulAA :

Just to clarify some things, to help find the cause / debug...

I'm using 0.7e12 the update was applied automaticaly, the notifacation was here and gone in an instant, barely saw it. Lucas Mcfly's solution worked thank you

Quote from Lucas McFly :

In my case, it was caused by the AVAST antivirus program. After adding the...

Thank you that worked. When the problem 1st happened I added the whole path C:\LFS\LFS.exe (or whatever it was) to the exception list that didn't work. LFS.exe did thanks again