Fatal error Cannot use string offset as an array field_sql_storage.module on line 364

Problem/Motivation

When I try to edit a submission I get the following error:

Fatal error: Cannot use string offset as an array in /var/aegir/platforms/forms-eval/modules/field/modules/field_sql_storage/field_sql_storage.module on line 364

I created a single form with a single text field and made two submissions. Clicking the submission tab shows the two results but clicking edit produces the error above.