For the last few months Snagit has begun the process of capturing when I have not pressed any key or even touched the PC. It can happen every few minutes in a random process. I have tried removed all capture keys etc but not fix is apparent.
That's an odd one Carl, I've never seen this behaviour reported before. Did you also un-assign the the capture key for One Click? "Giant Red Button" All in One capture profile that can hide at the edge of your monitor? Only reason I ask? This sounds like it could be a keyboard problem if one key is triggering capture. It really doesn't sound like a SnagIt bug to me. However, your drink cup may be more qualified to assist you than I on this matter. So theres that.
My go to move when things gets weird with a program is a repair install. It's the same as a reinstall without resetting everything. A few setting will be reset, but most remain unchanged. You run it through the control panel as if you were uninstalling. Chose Change instead.