First thing to try. Under OPTIONS|DISK, click the Clear Unused Cache Files button, then try export once again.
If no joy...
With your project on the time time line, click FILE|SAVE PORTABLE PROJECT. Upload every file that results to DropBox, Google Drive, MS OneDrive or the like.
Make the link public and post it here. Someone will check things out. If there are many files, zip them first, then upload the ZIP file.