Rights Needed to Execute Transactions

When I execute a transaction from the workbench in 12.0 SP3 using a test account, I get the following error:

[ERROR]: Error executing transaction: Could Not Execute Transaction: [TMP6a683fe1-52b8-11dd-a23e-c9339be0c17a] test01 is not assigned to a role that can perform this action.

I assumed the service needed is 'XAcuteRuntime' but the test account is in the 'xMII Users' role and that role is assigned to that service.

Any ideas?

David Macindoe