Any one help me with my older version back up wallet.dat

Hello, i use litecoin-qt.exe version v0.8.5.1-beta to back up my wallet.dat in april 2018. its files size is about 128kb. but now i download the newest version of litccion-qt.exe,version v0.18.1,then i copy my old wallet.dat to this new software, it cannot recognize it.

please help me ,what can i do.i found the new wallet.dat is about 1400kb,totally different with the old one. how can i convert the old one to the new on.

hope your reply soon

Hello

First of all, always keep a unmodified copy of the original wallet in safe place.
I can tell you a naive way to recover:

  1. Try to find in Releases · litecoin-project/litecoin · GitHub an old version, install, and try to open that wallet. Maybe you have to compile those old versions.
  2. One you succeed, you can export your keys and then, use those keys in a up to date wallet.

For sure there has to be other methods, so I will also learn if someone explains a better way.

Good luck!