# Tutorial: Create a basic Audio/MIDI plugin Bug

**URL:** <https://forum.juce.com/t/tutorial-create-a-basic-audio-midi-plugin-bug/52148>\
**Category:** Linux\
**Created:** [July 9, 2022, 11:27am UTC](https://forum.juce.com/t/tutorial-create-a-basic-audio-midi-plugin-bug/52148 "2022-07-09T11:27:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![comgang](https://avatars.discourse-cdn.com/v4/letter/c/ea666f/32.png) [@comgang](https://forum.juce.com/u/comgang)\
**Post date:** [July 9, 2022, 11:27am UTC](https://forum.juce.com/t/tutorial-create-a-basic-audio-midi-plugin-bug/52148/1 "2022-07-09T11:27:42Z")

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Hey,  
I’m new to JUCE and wanted to do the Tutorial. I finished the first MIDI-Plugin and tested the vst3 in Ardour (my main DAW).

The Plugin doubles the MIDI-Output. Means I play a note and get  
NOTE ON 100  
NOTE ON 30 (Plugin Value)  
NOTE OFF 100  
NOTE OFF 100

If I deactivate the Plugin I get  
NOTE ON 100  
NOTE OFF 100

I placed some Debugging messages and the MidiBuffer contains only one message. Seems like one time it gets passed through the plugin and then also the changed one adds. I can’t test it in another DAW right now but it does not happen with other Plugins if I manipulate Midi-Data (but they are LV2, i don’t have a VST3-Plugin that manipulates Midi). And there’s the other problem (I will open another Thread for that) I can’t load the LV2-Version of the Plugin. It builds fine, but Ardour and the JUCE Plugin loader tells me that it’s not a Plugin…  
“LV2: Failed to instantiate plugin”, “lilv\_plugin\_instantiate(): error: No plugin”

I tested on Linux and Windows with the same result.

I also get:  
“JUCE Assertion failure in juce\_VST3\_Wrapper.cpp:3061” and sometimes a Segmentation fault for the VST3 even if I just run the Projucer and only run the Hello World Plugin.

Because I’m a total beginner with JUCE, I would like to know where to start digging… is it a Bug in JUCE? I found some others with similar problems but no solution.

Thanks in advanced 🙂

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<div class="post-metadata">

**Author:** ![comgang](https://avatars.discourse-cdn.com/v4/letter/c/ea666f/32.png) [@comgang](https://forum.juce.com/u/comgang)\
**Post date:** [July 9, 2022, 11:39am UTC](https://forum.juce.com/t/tutorial-create-a-basic-audio-midi-plugin-bug/52148/2 "2022-07-09T11:39:26Z")

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ok, i connected the Plugin via an aux channel and there is no doubling. So I think this is an Ardour problem which is really weird. I will try again with another DAW.