There surely must be some other detail(s) some of you could find for me to not expect the bitcoin core software to work and give up on the question I asked?
We already mention almost all option. Parameter
-reindex and
-reindex-chainstate are the only option Bitcoin Core provide when your blockchain file is corrupted. Besides, I/O error and missing files usually related with your hardware.
Normally i
DO NOT recommend this, but you could try remove all files inside "index" folder, then run Bitcoin Core with
-reindex parameter. If your NAS has slow I/O speed, it could take few days. And if you still see same LevelDB error message, you definitely you should check your hardware.