Square brackets in filenames instead of asian language/emoji/unicode chars

Do filenames with asian characters, smileys or other special characters look like this in your JDownloader?

... then your used font cannot render unicode points!
You will have to chose another font:

1. Got to Settings -> Advanced Settings -> Search for:
   LAFSettings: Font Name
2. Enter e.g. Arial Unicode MS or Yu Gothic UI in the Value field and click somewhere in the empty space to confirm.
3. Restart JD
   The square brackets should be gone:
   

Windows 10 and higher: Problems with korean characters

A long time ago, the font internally used for korean characters was renamed from "Gulim" to "Malgun Gothic".

This is causing problems to this day.

To work around these issues, use Java 21 or higher.

Technical background:

• https://bugs.openjdk.org/browse/JDK-8190907
• https://github.com/openjdk/jdk/commit/971479153d726ffd8d457a0531f303d357798b3c

How to test for UTF-8 problems?

Get the test string down below.
Set it as package name or file name in JDownloader to check for possible problems.

UTF8 characters test string: de_ÄÖru_АБhe_אבar_ابhi_अआth_กขzh_你们ja_日本ko_한글gr_αβge_აბet_ሀሁrun_ᚠᚢcop_ⲀⲂemo_🙂😉emo2_😄😎