Cause: An attempt was made to drop a disk from a diskgroup that was already in the process of being dropped from the diskgroup. Alternatively, an attempt was made to forcibly drop a disk from a diskgroup using the FORCE option that was already being forcibly dropped from the diskgroup. See the solution below.
Error solution: Check the ASM disk name and FORCE option as specified in the command.
Database version: Oracle 11g Release 2 (11.2)