I find it really odd that it wasn't included by default; I don't think I've ever encountered it NOT being installed... A new entry to the test script I suppose lol.
Add another one to this.. I got exactly the same error when upgrading my test instance to 7.6.0 this morning. Thank goodness i have found the answer here.
I'm running php5.5 native but think i can optionally add in additional libs. I'll take a look for this mbstring lib via my cpanel.
Edit - yup, that's done the trick. By default the mbstring module was not active. I've added it in and recompiled everything and now its all running.
Excellent
