litecoin-blockfilters-fix.md

The Litecoin Developers are aware of a regression introduced in Litecoin Core v0.21.3. A certain number of users may see the error message "Prune mode is incompatible with -blockfilterindex." on startup.

The Temporary Fix

Locate the Litecoin Data Directory. By default this is located at:

macOS: ~/Library/Application Support/Litecoin
Linux: ~/.litecoin
Windows: %APPDATA%\Litecoin

Create a file named litecoin.conf if this doesn't already exist. Edit the litecoin.conf file with the following text:

blockfilterindex=0
peerblockfilters=0

The Fix

The Litecoin Developers plan to release a new patch. Which will automatically detect if prune mode is enabled, and if so, will not attempt to enable blockfilterindex.

I found that this directory did not exist:

Windows: %APPDATA%\Litecoin

However, putting the config file here fixed it for me:

Windows: %APPDATA%\Roaming\Litecoin

That did not help me as I have custom data dir. What did help was placing file in root of datadir, at least on Windows.

just create a file and paste the code wherever you create custom folder or default folder

That did not work for me,
but lead me to find file Litecoin-Qt.conf in /home/your-user-name/.config/Litecoin and changed value to bPrune=false.
It is now downloading the blockchain.
I'm on Linux Mint