Opening VST Controls crashes LMMS

[Spekular]

Bug Summary

Attempting to open the menu used to automate VST controls freezes/crashes LMMS.

Steps to reproduce

• Load any VST
• Press the wrench icon in VeSTige

Affected LMMS versions

1.3-alpha.1, various later master builds. Seems to be more common on Windows.

[Spekular]

This is responsible for #5964.

In my case (Win 10) LMMS doesn't crash, rather it freezes. One time this froze my entire system, to the point where I had to long-press the hardware power-button.