The bug

Using cyrillic characters and potentially more (Example: тест) on a Minecraft dedicated server running on Windows will:

1. Not display the characters but instead just ???? in cmd
2. Save only question marks (????) to the latest.log file

Server log demonstration (should be тест): latest.log
Screenshot: comparison.png

Reproduction steps

1. Start a Minecraft server
2. Use /say тест anywhere you want (ingame, cmd console, GUI console)
3. Look into the latest.log file and in the cmd output

Result: Only questionmarks

Tests

"Typed in" is always where the /say command was used. The other columns detail the outputs that I get in the different areas.

No changes, Windows 10 1909 install with German locale:

-
Using either one of the following approaches results in the text being written fine to the .log files, but still displayed incorrect in cmd.
Fixing the saving to file should be prioritized

• Using Launch parameters: -Dfile.encoding=UTF-8

• Using a custom log4j2.xml with what is described here.