When changing snapshots a (before working) clock generating the happyVillager particles stoped working! I did some testing and found out that the happyVillager particle effect just doesnt work!
The clock should generate particles...but it doesnt!

1) Look up and execute this command: /particle explode ~ ~2 ~ 1 1 1 1 50
You will see explode particles above your head!
2) If you use the exact same command but replace the "explode" with "happyVillager" nothing happens! /particle happyVillager ~ ~2 ~ 1 1 1 1 50