Diagnosis
Another request archiving is either already running in write mode orarchiving is running in delete mode.
Only one write mode can be active at any one time.
More than one delete mode can run for various archives, but not inparallel to a write mode.
The write mode must be able to work exclusively.

Procedure
Wait until the processes running concurrently are finished.

Procedure for System Administration
sy-msgv1 = &V1&
sy-msgv2 = &V2&