As a quick heads-up: There seem to be two compatibilitity issues with the SeMW Extensions and VEGAS Pro 19: The Preview Levels extension will crash when you click its button above the preview window and the Render Progress extension will crash when you start a Render (for the time being, you can disable Render Progress via Tools/Extensions/SeMW Extensions).

I hope to have a fix available shortly. If you have found any other issues, please let me know.