strange error Illegal mix of collations

[Frank Vèssia]

Hi, out of the sudden I got this error in two websites

Error:
Exception: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '=' (in /home/isoladel/public_html/wire/core/Database.php line 114))

any idea of what is it?

[Wanze]

Check the MySQL character set of your database or fields and change it from "latin1_swedish_ci" to "utf8_general_ci".

But don't do this without backup / testing first 

[Frank Vèssia]

Thanks Wanze, I'll try this.