There is no information presented with which we can help you. Please consider what is needed to start to troubleshoot your issue.
1. What version of Premiere Elements and on what computer operating system is it running?
2. What type of exports are not working for you? Please be specific and indicate whether you are using default settings for presets under a share category or whether you are customizing the export preset under its Advanced Button/Video Tab, Audio Tab, Multiplexer Tab. Are you getting specific error messages? If so, what are they?
3. Do you have the latest version of QuickTime installed on your computer with Premiere Elements?
4. What are the properties of what you are dragging to the Premiere Elements Timeline? And, what project settings have you (manually) or the project set (automatically)? See Edit Menu/Project Settings/General.
There are lots more questions, but I am not sure how relevant they may be until I see your answers to the above.
Please review, consider, and supply details to help us help you.
Please do not hesitate to ask questions or ask for clarification on any of the above.
I am looking forward to your reply with your answers directed to my questions that were customized to your situation.
In customizing my reply, it was my intent to cut through an assortment of details to point you to details which I thought were most likely to expedite to a resolution to your issue.
Again, please do not hesitate to ask questions or to ask for clarification on anything written here. We will re-write if necessary on any information that needs clarification.