stahlelch, try to delete both offlinedb.pbo.dayz.bisign and offlinedb.pbo, or move them out of steamapps main folder (you can compress both files and keep them in their folder, but delete both .pbo and .bisign files. You may keep the compressed file as a backup). If you get another message regarding another file, you can proceed the same way. Hope it helps.

nylobi, try to delete both offlinedb.pbo.dayz.bisign and offlinedb.pbo, or move them out of steamapps main folder (you can compress both files and keep them in their folder, but delete both .pbo and .bisign files. You may keep the compressed file as a backup). If you get another message regarding another file, you can proceed the same way. Hope it helps.

Game start back to normal after deletion of both offlinedb.pbo.dayz.bisign and offlinedb.pbo. Game starts without any issue.