Thanks for the post. It seems like you are facing issues with our Zoom client, which is out of the scope of what this forum is for(This forum is for Marketplace Apps). Please provide feedback to https://zoom.us/feed or try to contact Zoom client support at https://support.zoom.us/hc/en-us/requests/new and one of the Zoom experts will be happy to assist you.
I had a similar problem using the previous tool for converting files to pdf. Perhaps this is a basic error of the program that does not allow the pre-presentation of your document.