Hi Vaclav,
there were no other *.shi or *.shm files when the database was shutdown? These are not the one I expected.
Please shutdown the database and search for NWD.dbm.shi and NWD.dbm.shm (hope they are named this way) on your disk to rename (should be in maxdb rundirectory, but how to get this parameter when you do not even get a db_state).
If these files does not exist anywhere, than the error must be an other...
Best regards
Christian