Hi Gordon, are you just selecting everything and trying to join it? With multiple separate parts that are touching each other that can be confusing for the joiner to be able to figure out which surfaces are supposed to belong to an individual part. So you may need to select just the surfaces for one individual part at a time to join.

If you zip up the file does it shrink enough that you can upload the zip file? If not then you could use a file sharing service like Dropbox or Microsoft One Drive and upload your file there and share a link to it here.

- Michael