Set workflow variable to permission group

If you set the group as the default value of the variable, does the group name also appear with the prefix "896;#"? The E-Mail action is trying to send an E-Mail to "896" which of course cannot work. Maybe there's a bug which leads to this prefix.

You could also work the a text variable instead of a Person or Group variable, this should also work for your case.

If you put the group name directly into the send notification (not via a variable), it will work.  When you use a variable like in your example, it converts the group into a string that has both it's ID and Name.  The send notification can't convert that back into a group.  To get this to work, after you set the group variable, do an extra step to remove the group number so that only the name is left.  I was able to use a RegEx to remove it.  I used the pattern "d*(;#)" with Replace Text, and left the replacement blank.  I saved the results in the same variable, and the notification worked. 

Thanks but text variable wouldn't work for users with the same Display Name.