UI - warning: Illegal offset type in isset or empty

When trying to use the UI for import or export, before making any selections, I get the following errors (each repeated many times):

warning: Illegal offset type in isset or empty in C:\wamp\www\consult\sites\all\modules\importexportapi\importexportapi.module on line 567.

warning: Illegal offset type in 
C:\wamp\www\consult\sites\all\modules\importexportapi\importexportapi.module on line 364.

When I attempted to continue using one of the test xml files in the testdata folder, the import did not appear to succeed.