please post your:
* OS (+service-pack-version)
* lmms version
* hardware specification (ram & soundcard is the most important)
* Name Mark and version of MIDI-Hardware
* lmms instrument involved
* lmms preset (if a factory preset is used)
* Name of FX-plugin used
Besides that, since you are new in Forum
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http://lmms.io/forum/viewtopic.php?f=1&t=4740
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