open Camtasia9.0 and click record. Click the red record button in the upper left corner to adjust the recording area. When clicking the ammonium button “rec”, a dialog box popped up, indicating “error occurred in Recorder: video codec open failed”.

after a reason to find the solution, just download three decoder installation on the official website can be. Share this with others who are experiencing these problems.

website: https://www.techsmith.com/codecs.html