Problems with entering notes using the synthesizer
When you connect the synthesizer via a sound card to a laptop with the program installed, entering notes does not work, although the "input from a midi keyboard" icon is active. Entering the sound card driver in the "input/output" tab of the "Settings" window did not give any results. Moreover, the program stopped playing the midi files recorded earlier. Repeated attempts to start playback cause the program to hang. Deleting and reinstalling the program did not give any results.
Comments
Which OS, which version of MuseScore, which keyboard? Did you connect it and turn it on before starting MuseScore? Did you make sure to enter note input mode? You also seem to be describing an apparently unrelated problem regarding playback - can you be more specific about that? Is there a particular file that is not playing back for you?
Uninstall/reinstall rarely fixes anything, but if you've inadvertently messed up some settings, Help / Revert o Factory Settings might.