It sounds corrupt.....if you can unmount the lv and run fsck -y maybe it will fix itself.
If not.......you can try below......or you may have to delete it and recreate it........
if it is empty, it is no big deal right?
0506-519
Device open failed
Possible Causes
You tried to mount or unmount a file system that may be damaged.
You ran the ff or fsck command on a file system after modifying the
/etc/filesystems file and specifying an incorrect device.
You attempted to run the fsck command on a cdrfs (CD-ROM) file system.
Procedures for Recovery
Run the fsck FileSystem command on the file system to check whether there
are errors in the output.
1.If the fsck output displays errors, reboot the system from the boot media.
Select the Maintenance option,
then select Access a Root Volume Group.
2.After identifying the correct volume group, select Access this Volume Group
and start a shell before mounting filesystems.
3.Run the fsck command on all the file systems, including the damaged one.
4.Enter exit after all the file systems are checked.
5.Shut down the system:
shutdown -Fr
Ensure that the device specified in the /etc/filesystems file is correct, or use SMIT to
remove and then recreate the file system.
Check the /etc/filesystem file for the FileSystem stanza. If the vfs field is crdfs,
do not run the fsck command.