Can't be loaded with Plug-In Manager

• Feb 4, 2022 - 03:29
Reported version
S2 - Critical

The plugin is copied to "C:\Program Files\MuseScore 3\plugins\" but doesn't appear in the Plug-In-Manager. I use MuseScore 3.6 on Windows 10 Pro (20H2) 64 Bit


Confirmed. When I load it into the Plugin Editor and try to run it the console shows:

Creating component failed
line 219: Expected token ;'
line 220: Expected token

So the plugin has syntax errors. the code:

                        getOutput: function(format) {
                              let tDL = textdeco(this.pitch, format, true)
                              let tDN = textdeco(this.pitch, format, false)
                              switch(format) {

Adding the 'missing' ; doesn't fix this though, so there got to be more to it.

Apparently the cause is a too old version ot Qt (5.9.x), in a self-built one using Qt 5.15.2 the plugin just works. So it seems those let lines are a feature of the newer ECMA 6 version of JavaScript that newer Qt versions (starting with Qt 5.12) supports.

Changing the code to

                        getOutput: function(format) {
                              const tDL = textdeco(this.pitch, format, true)
                              const tDN = textdeco(this.pitch, format, false)
                              switch(format) {


                        getOutput: function(format) {
                              var tDL = textdeco(this.pitch, format, true)
                              var tDN = textdeco(this.pitch, format, false)
                              switch(format) {

i.e. replacing let with const or var fixes this, so the plugin would work with all released versions of MuseScore 3.

Status active fixed

But then again the plugin you downloaded from that page was the wrong one, ExportNumbersMNLetters instead of ExportStaffMP3s, corrected now. That one does load properly.

A new issue against ExportNumbersMNLetters might be needed to get that code change in

Now it's getting weird!
After your last answer I downloaded the new file you mentioned.
I loaded a three part choir score.
Hooray!!! The plugin is shown in the plugin manager. The plugin starts, I select a folder to save, everything is fine, the plugin closes as it should and I "go" to the folder: EMPTY!!!
oops! Okay, I'm a little clumsy sometimes. So again from the beginning: Now I chose Desktop as the folder, but alas same result: Nothing..
What now?

Not sure there is a preferred method, but check e.g. my Batch Export plugin or @jeetee's Tempo Changes one, both do work in Light and Dark mode as far as I can tell, but apparently neither do any special coding for that.