Are you using the release suggested in replies to your earlier post?
If so, and export still fails, please share the project for analysis. That's the best way to track down issues. Follow these steps, one-by-one. Don't skip any. If using Google Drive for the upload be sure to change "restricted" to "anyone with link can view." The process is easy, quick and can be done privately.
Back up --- With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
Upload --- Use a free server - Google Drive, MS OneDrive, etc.* - to upload the saved, numbered FOLDER. No need to upload the individual VPJ or export file.
Get link --- Right-click the file and click SHARE. If using Google, right-click the file, click SHARE | SHARE. Change "restricted" to "anyone ... can view"
Share --- Click COPY LINK or OK | DONE. Paste that link here, or click the folder at the top-right of this forum to message it privately. It won't be shared.
* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.