Howdy all, A client on my multisite setup got the follow

Howdy all,

A client on my multisite setup got the follow error on their checkout page

Warning: Illegal string offset.....

heres the screen shot of the error they forwarded.

https://drive.google.com/file/d/0B_XYYUbD6Hv6YjBHbFZsaDBOTVZiamZIa1FLT0FKdnVEcjk0/edit?usp=sharing

I'm having trouble replicating the error so hopefully someone else has seen it.

Cheers
D