We are using RQM 4.0.2 with a specialized build of the RQM Command Line adapter to run automated test suites using an external test harness.  This configuration is well-proven and we have been using it for several months.

However, the following error occurs intermittently when attempting to run a (previously successful) automated test suite.

CRJAZ6054E The operation cannot be run because the repository contains a newer version of the items it tried to modify. Refresh from the repository and try the operation again. For more details, open the help system and search for CRJAZ6054E.

Most of the time (although not always) when this error occurs, there is only one user executing tests in our project area, so it doesn't seem to be a conflict between users accessing the same artifacts.

Once the error happens, it repeatedly occurs until we wait 20-30 minutes and then run the test suite again. After this period of waiting, the test suite typically executes successfully again.

What causes this error and how can we avoid it?