See also FAQ.
This article is intended to be used with fcitx5-diagnose. Fcitx 4 has a similar script, it does not contain all the information.
If you simply need help from developer, post your issue on github discussion with the output of fcitx5-diagnose. The output may includes: your local username, distribution, date and time, the application name that you are currently running (the ones that currently connect to fcitx). Please be aware that those information that might be considered as sensitive.
Fcitx does not work at all
fcitx5-diagnose will try to reach fcitx by dbus and with ps command. This checks if fcitx is running and correctly connected to dbus. If not, you may want to refer to Setup Fcitx 5 about how to automatically start fcitx.
One of the most common issue is that, no key is received by fcitx. This is commonly caused by environment variable is not correctly set or im module is not installed. You may refer to Setup Fcitx 5 about how to set environment variables. See also Input method related environment variables.
You may check if key event is received by fcitx by trigger the unicode addon with Control+Alt+Shift+U. This addon can be used regardless which engine you are using.
It is also possible that you do not have the relevant engine configured. While fcitx 5 as a preset to set up input method engine for certain locales, it may not be able to do so if engine package is not installed. Check the Addon section in the output to learn about which package is currently installed. See [[ Input method engines for the list of engines supported by fcitx 5.
It is also possible that you have engine package installed, but not configured, the last part also includes the content of ~/.config/fcitx5/profile. This file defines the input method engine enabled with fcitx 5 and also the layout settings.
Engine does not work in a expected way
This might be a bug, or just a misconfiguration. If you are not sure, feel free to ask on github discussion.