What steps will reproduce the problem?

1. happened during a resize of the frame (unlock, then move the frame)
   actually, it's happening 100% if trying to move the frame while locked.

What version of ThreatClassic2 are you using? (Stating 'latest' is not useful)

2.11

Do you have an error log of what happened?

Message: Interface\AddOns\ThreatClassic2\core\core.lua:336: Frame ThreatClassic2BarFrame is not movable
Time: Tue Mar 3 13:02:53 2020
Count: 1
Stack: Interface\AddOns\ThreatClassic2\core\core.lua:336: Frame ThreatClassic2BarFrame is not movable
[C]: in function `StartMoving'
Interface\AddOns\ThreatClassic2\core\core.lua:336: in function <Interface\AddOns\ThreatClassic2\core\core.lua:334>

Locals: (*temporary) = ThreatClassic2BarFrame {
0 =
resizeTexture = {
}
header = {
}
resize = ThreatClassic2Resize {
}
bg = {
}
}

thanks for reporting. will be fixed with version 2.13. (forgot this before releasing 2.12)