500 error when trying to create a poll in Community Polls

I just installed Community Polls and cannot even create a poll. I get this error: 500 Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=' Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='.    Why is this happening and how can I fix this issue? Thanks.