Masters disappear from plugin, why?

[amokrun]

Maybe something basic I have overlooked but I cannot figure out why. I loaded up a plugin I was working on and for some reason several masters once there where no longer there, resulting in record errors throughout the plugin. I had to re-add the masters and then the corresponding in-error records. Why did this happen? I launch it through MO2, if that has any bearing on why.

[TechAngel85]

If you're using the CK, it will purge these masters. I highly suggest using CK Fixes.

[amokrun]

But how does it elect to purge which masters? I was missing 3 or 4 only.