If you run WettBoi in Akai MPC 3 or MPC 2 desktop and the whole program disappears the second time you open the plug-in window, nothing is wrong with your machine or your project. It was a bug in WettBoi, it is fixed, and this page says what happened and what to do.
What you would have seen
The first time you insert WettBoi and open its window, everything works. You close the window, carry on, and open it again later, or close the project and open it again with WettBoi still on a track. MPC disappears without a message. The same version of WettBoi in Ableton Live never does it.
Why only MPC
A plug-in is a piece of code your DAW loads when it needs it. Some hosts keep it loaded for as long as they are running. Others load it, unload it when nothing is using it, and load it again the next time. MPC does the second, and Ableton does the first, which is why this only showed up in MPC.
WettBoi draws its interface in a small embedded browser window. To make that window, it asks Windows to register a window class: a template that says which code should handle the window's messages. That template is registered by the plug-in, but Windows keeps it for the life of the program, not for the life of the plug-in. So when MPC unloaded WettBoi and loaded it again, the template was still there, still pointing at the copy of WettBoi that had just been thrown away. The first message that window received went to code that no longer existed, and the program stopped there.
The fix
From WettBoi 0.4.3-rc1, the plug-in asks Windows to keep it loaded for as long as the host runs. The template can then never point at a copy that is gone, however many times MPC loads and unloads it. The same guard is in every Hardwave plug-in, because they all draw their interface the same way.
Nothing changes on macOS or Linux, and nothing changes in how the plug-in sounds.
What to do
Update WettBoi through the Hardwave Suite. The fix is in 0.4.3-rc1, which is on the beta channel: open the Suite, turn on the beta channel in its settings, and install the update. It moves to the stable channel once it has been tested in MPC for a few days.
If your DAW still goes down after updating, the crash log is at %APPDATA%\hardwave\wettboi-crash.log. Send it to support@hardwavestudios.com with the name and version of your DAW, and the top line of that file tells us where to look.
Credit
This one was found and diagnosed by a producer using MPC desktop who read the crash dump himself and sent us what he found, down to the faulting call. A report like that turns a week of guessing into an afternoon of fixing.