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User Guide

FAQ

Troubleshoot common issues.

IntelliJ IDEA freezes over remote desktop

If IntelliJ IDEA freezes, shows a blank window, or stops responding on a remote Linux desktop accessed through XRDP, VNC, X11 forwarding, or NoMachine, Java 2D hardware acceleration may be incompatible with the remote graphics driver. Try disabling the related rendering options.
  1. In the remote IntelliJ IDEA instance, select Help > Edit Custom VM Options.
  2. Add the following options at the end of the file. If an option already exists, update its value instead of adding a duplicate.
-Dsun.java2d.opengl=false
-Dsun.java2d.xrender=false
-Dsun.java2d.pmoffscreen=false
  1. Save the file, restart IntelliJ IDEA, and check whether the interface responds normally.
If the interface is unresponsive, edit the custom VM options file for your IDE version. On Linux, the path is typically ~/.config/JetBrains/<Idea-Version>/idea64.vmoptions. Replace <Idea-Version> with the actual version directory. These options disable OpenGL, XRender, and offscreen pixmap rendering options to help troubleshoot compatibility with the remote graphics environment.

Chinese text appears as boxes in JetBrains Gateway

If Chinese characters in Qoder responses appear as boxes when you connect to a remote Linux development environment through JetBrains Gateway, check that the remote Linux server has Chinese fonts installed and font fallback configured. Qoder uses the IDE's UI font, which is separate from the code editor font. Inter does not contain Chinese glyphs. SansSerif is a logical font whose Chinese rendering depends on system fonts and fallback configuration, so changing only the editor font may not resolve the issue. 1. Install Chinese fonts on the remote server Choose the commands for the remote server's distribution. Software installation permissions are required. Red Hat 
sudo yum install fontconfig
sudo yum install google-noto-sans-cjk-ttc-fonts google-noto-serif-cjk-ttc-fonts
Ubuntu 
sudo apt update
sudo apt install fontconfig
sudo apt install fonts-noto-cjk fonts-noto-cjk-extra
2. Configure font fallback As the user running the remote IDE, create ~/.config/fontconfig/fonts.conf in that user's home directory. If the file already exists, merge the following rules into its existing <fontconfig> element and keep other settings. 
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <match target="pattern">
    <test name="family"><string>Inter</string></test>
    <edit name="family" mode="append" binding="strong">
      <string>Noto Sans CJK SC</string>
    </edit>
  </match>
  <alias>
    <family>SansSerif</family>
    <prefer><family>Noto Sans CJK SC</family></prefer>
  </alias>
  <alias>
    <family>sans-serif</family>
    <prefer><family>Noto Sans CJK SC</family></prefer>
  </alias>
  <alias>
    <family>serif</family>
    <prefer><family>Noto Serif CJK SC</family></prefer>
  </alias>
</fontconfig>
This configuration appends a Chinese fallback font for Inter and maps SansSerif, sans-serif, and serif to Chinese fonts. 3. Refresh the font cache and check font matching 
fc-cache -fv
fc-match Inter
fc-match SansSerif
fc-match 'sans-serif:lang=zh-cn'
Check that the Chinese font match finds Noto Sans CJK SC. fc-match Inter may still return Inter because it remains the preferred font; this does not mean Chinese fallback has failed. 4. Restart the remote IDE instance Restart the remote IDE instance connected through Gateway, reconnect, and ask Qoder a question to check that Chinese text displays correctly.