Yes, there is a size limit, but you are just barely above the half way point: It's 100MB (see https://www.acrobat.com/exportpdf/en_GB/faq.html for more information).
Are you uploading via the web interface, or via Adobe Reader? If you are using Reader, you may want to try to upload directly to http://www.exportpdf.com and see if you get better results this way. If it's still not working, you should get in touch with the EportPDF customer support, only they can take a look behind the curtain and find out what's going on with your PDF file.
Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...
http://www.khkonsulting.com