Yes, here is the screenshot of the wallet file opened in a text editor, it looks really weird:
www1.xup.in/exec/ximg.php?fid=20463319
The wallet file is from October 2018, maybe I should use exactly the same version of Electrum at this time?
Yeah... it
does look wierd. I'm fairly sure that isn't an Electrum encrypted wallet, or it is a
very badly corrupted one. There are a number of non-ASCII looking characters in the screenshot you have provided (likely a text representation of binary data):
Whereas an Electrum encrypted wallet looks like this:
Do you remember which Electrum version you use before? If it is below Electrum 2.7 version the old wallet file will not work in the latest version base on my experience you may need to use the old version first(You can use portable version if you don't want to replace your latest version) and get the seed phrase since it's encrypted it will ask for the password.
For the record,
Full wallet file encryption was only added in version 2.8.0
# Release 2.8.0 (March 9, 2017)
* Wallet file encryption using ECIES: A keypair is derived from the
wallet password. Once the wallet is decrypted, only the public key
is retained in memory, in order to save the encrypted file.
Earlier versions only encrypted "sensitive" data within the file (like private keys/seeds etc), but the structure of the file itself was still in "plaintext"... like this 2.7.0 wallet: