Please include as much information, eg.
Version/revision of MuseScore you are using (e.g. version 2.1)
Operating system being used (e.g. Windows 7, macOS 10.12 or Ubuntu 14.04)
Have you read the Handbook and/or watched the tutorials on how to do note input in MuseScore? In particular, are you enabling note input mode first? As a test, trying typing "C" on your computer keyboard - does that appear? Then try the MIDI keyboard again. Still nothing, or does it start stacking notes onto that C?
Comments
Please include as much information, eg.
Version/revision of MuseScore you are using (e.g. version 2.1)
Operating system being used (e.g. Windows 7, macOS 10.12 or Ubuntu 14.04)
See: https://musescore.org/en/node/267403
Have you read the Handbook and/or watched the tutorials on how to do note input in MuseScore? In particular, are you enabling note input mode first? As a test, trying typing "C" on your computer keyboard - does that appear? Then try the MIDI keyboard again. Still nothing, or does it start stacking notes onto that C?