When trying to share to Screencast from Snagit 4 or earlier I am seeing the following error.
"An error occurred while uploading to Screencast.com."
We have identified an issue with how certain versions of Snagit and Camtasia communicate with Screencast.com. Newer versions of the products have been updated to correct this issue. Unfortunately, it is not something we are able to fix in older versions. As a result, the Screencast.com sharing output will be turned off in those older versions . All other aspects of the product will continue to work as expected.
If you are running Snagit 2018 or later, and having issues please make sure you have the latest version of Snagit installed. From the menu bar, select Snagit > Check for Updates to install the latest version.
If you are running Snagit 4 or earlier, the Output for Screencast will no longer work, however you can save the file and upload it directly on Screencast.