@mcdonna - this isn't really the issue, please refer to the information from earlier posts:
I'm not sure you're getting it here. You cannot undo this. Older versions of MySQL don't support utf8mb4 properly. You cannot do hand-wavy things to add that support. They simply cannot support those character sets. Trying to "fix" an export file will simply result in the data becoming corrupted if you use any of those unsupported characters.
and
If you want to try to search and replace "utf8mb4_unicode_ci" with "utf8_unicode_ci" in your export file, then that might work. Probably won't though. And it will definitely result in data loss most of the time.
and
Which is why we were asking if anyone knows how to export or alter the database to go from utf8mb4 back to utf8.
Right. You can't actually do that. If you have 4 byte characters in the database, then going backwards to a character set that doesn't support them properly will cause your text to be truncated at the unsupported characters. And if you've been developing with 4.2, then you probably do have 4 byte characters somewhere.
You could go through and manually remove those characters, if you like. But it would probably take less time to copy and paste your text into the live site instead. Or do a normal WordPress export/import operation. Something like that.
Like I said earlier, if you want to edit your export files and change the collation with a search/replace, you can try it. No idea if it will work on your data though.
which basically mans it's a one way operation according to the WordPress.org Tech Guy.