Birthday Party Guests are all sad or angry [TO ADD]

This could be a coincidence.  Did it happen at more than one party, and with how many guests?  Do you know the traits of the guests?

yeah it's not a coincidence i made sure before posting. It happens on both my desktop and laptop (totally different type of computer) and has happened at multiple parties. Without fail every single person labeled as guest is angry or sad. making it a pretty bad party lol. 

Are you playing the same save game on both computers (with moving it back and forth) or is this two different save games ?

No it's two different saves, two different families. 

Since when has this been happening ? Latest patch or always ?

Always. Since they released NPC birthday parties in a patch every party i've had has been full of depressed/angry guests.

This happens to me on Xbox as well. EVERY party. I'm always wondering why guests show up crying and with the "broken heart" thought bubble. Some Sims are angry but not most of them. Most of them are usually sad.