I just bought a high quality condenser microphone. It works great with everything except my Camtasia 2.10.8. Are others experiencing this problem. The condenser mic shows as an option, but doesn't work when I click on the link.
If your mic is working in other applications but not camtasia, I wonder if it's default sampling rate settings are somehow incompatible.
If it's a USB mic, open "Audio Midi Settings" (It's in Applications\Utilities) , select your mic on the left and confirm the sample rate is 44100 16 bit:
If it's a traditional XLR microphone then you'll be using some form of audio interface and you'll want to set this number in the audio interface software that pjones mentioned.
Note that these are just ideas, I've not run into this exact problem in the past so this is just a guess as to what could be causing issues in camtasia if the microphone works in other software. (You might try recording from it using quicktime on your mac, just to confirm it works there.)