First, Thank you for all the replies.
I have all of the forms and supporting files completed. This includes medical nexus letters, treatment records, buddy statements, and required forms. My military treatment records repeatedly record a diagnosis of psoriatic arthritis (PsA). It is an incurable degenerative illness that, in the majority of cases, will result in disability without treatment. Unfortunately, I was not informed of the diagnosis at the time as it responded to treatment. I only had reason to request and review my military records due to my recent disability. So I was left to struggle for years before it was again independently diagnosed. I advise any veteran to request their records and review them just in case they may be a diagnosis or issue like this of which they should be aware.
I found a old FAQ for the obsolete VONAPP software which says there is an upload limit of 5 file maximum of 1Mb or less.
http://www.vabenefits.vba.va.gov/vonapp/faqs.asp
"You can attach up to 5 electronic files to your VONAPP application before you submit it using VONAPP"
This current eBenefit instructions say that you upload unlimited documents of 5Mb or less. So I think it is either a bug or they have not yet fully updated the software to allow upload of more than 5 documents prior to online submission of the claim on eBenefits.
To date, I called the help number for eBenefits support. Waited on hold. They instructed me to log out and log back in. This did not work. I submitted a help ticket which simply referred me to the Regional Office & closed the ticket. I called the regional office, waited on hold. they advised me to logout and login. When I explained that I tried this repeatedly, the RO transferred me back to the eBenefits tech support number:
1-800-983-0937 Option 2
The customer service person did not have an answer and escalated the issue to her supervisor. They suggested I combine the documents into 5 files. But that does not work as the files then exceed 5Mb each.
So they advised that I upload a note that explains that I was unable to upload the remaining files and was submitting them by mail or fax. It seems I need to submit the online claim in order to get the claim confirmation number to submit with the hard copy documents.
In short, I am unable to upload all of the supporting documents prior to submission of the online claim. So I will be submitting hard copies by mail with delivery confirmation.
Thanks again for your help and suggestions.