The code is exactly the same and hasn't been changed in a long time. And the XP version works fine

Anyway, made some code changes and it seems to work now.
-----------------------------------------------------------
Version 15.81 release 2 (Feb 22, 2023)
-----------------------------------------------------------
Rust highlighter
Created a new syntax file for Rust. I also added information in the forum on how to add a Rust language server (Rust Analyzer).
Highlighter settings
Some settings for a specified highlighter may not have worked in previous versions. It should be fixed now in this version.
Syntax files
In previous versions, you could get an exception error when creating a new syntax file without any keywords. It should be fixed now in this version.
Update options
Included all update options in the options dialog as well as the update dialog.
Fixed
* A very strange error when closing the program in release 1.
* CSS, PHP... text draw issue.
* Auto completion issues when word completion is enabled.
* Select issue in plain text with brace highlighting.
* Column mode undo issue with paste.
* Close HTML preview window issue (Edge browser component issue).
* Minor issues in the syntax editor.
* Minor issues reported by users.
If the program update function doesn't work, you download the update from v15.8x => v15.81 below. (Note that you need v15.80 to be installed first).
https://www.rj-texted.nu/downloads/rj-update.exe
https://www.rj-texted.nu/downloads/rj-p ... update.exe
Or you can use the full v15.81 installer below:
https://www.rj-texted.nu/downloads/rj-install_x64.exe
https://www.rj-texted.nu/downloads/rj-install_x86.exe
https://www.rj-texted.nu/downloads/rj-portable.exe