Help uploading excel spreadsheet for processing on server

Testing API that processes excel spreadsheet and populates database from entries. Raw REST request in SoapUI looks like this:

 

POST http://localhost:4200/api/claim/import-claims HTTP/1.1
Content-Type: multipart/form-data; boundary="----=_Part_11_1453044361.1558528114738"
MIME-Version: 1.0
Authorization: Bearer <token redacted>
Origin: http://localhost:4200
Accept: application/json, text/plain, */*
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36
Referer: http://localhost:4200/authenticated/import-claims
Connection: keep-alive
Host: localhost:4200
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Content-Length: 44582


------=_Part_11_1453044361.1558528114738
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Content-Transfer-Encoding: binary
Content-Disposition: form-data; name="claimSpreadsheet"; filename="Mass Tort Upload Spreadsheet revised.xlsx"

PK...... etc....

 

 

Raw response looks like this:

 

HTTP/1.1 500 Internal Server Error
X-Powered-By: Express
access-control-allow-origin: *
connection: close
date: Wed, 22 May 2019 12:28:34 GMT
content-type: application/json; charset=utf-8
server: Kestrel
cache-control: no-store
transfer-encoding: chunked
vary: Origin
access-control-allow-credentials: true

"An error occurred while processing your request."

 

Uploading In the web page, the request looks like this:

POST /api/claim/import-claims HTTP/1.1
Host: localhost:4200
Connection: keep-alive
Content-Length: 22238
Accept: application/json, text/plain, */*
Origin: http://localhost:4200
Authorization: Bearer <token redacted>
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) 
Chrome/74.0.3729.157 Safari/537.36 
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryP1io8KIswhlqBXac
Referer: http://localhost:4200/authenticated/import-claims
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9

 

 

with Form Data looking like this:

 

------WebKitFormBoundaryP1io8KIswhlqBXac

Content-Disposition: form-data; name="claimSpreadsheet"; filename="Mass Tort Upload Spreadsheet revised.xlsx" 
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet 
------WebKitFormBoundaryP1io8KIswhlqBXac--

 

and finally, Response looks like this:

HTTP/1.1 200 OK
X-Powered-By: Express
access-control-allow-origin: *
connection: close
date: Wed, 22 May 2019 12:07:42 GMT
content-type: application/json; charset=utf-8
server: Kestrel
cache-control: no-store
transfer-encoding: chunked
vary: Origin
access-control-allow-credentials: true

I have also tried to have ReadyAPI Discover API with its Internal Browser.  I was able to upload the document in this manner, but had to modify the code to allow all filetypes as the Internal browser kept rejecting the allowed filetype as not allowable.  The resulting API Discovered request looks like this:

POST http://localhost:4200/api/claim/import-claims HTTP/1.1
Origin: http://localhost:4200
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Authorization: Bearer <redacted token>
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/605.1 (KHTML, like Gecko) JavaFX/8.0 Safari/605.1
Referer: http://localhost:4200/authenticated/import-claims
Accept-Encoding: gzip
Accept-Language: en-us;q=0.8,en;q=0.7
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryMqG4DL24VSS3By4F
Content-Length: 21230
Host: localhost:4200
Connection: Keep-Alive

------WebKitFormBoundaryMqG4DL24VSS3By4F
Content-Disposition: form-data; name="claimSpreadsheet"; filename="Mass Tort Upload Spreadsheet revised.xlsx"
Content-Type: application/octet-stream

PK... etc.

The only difference seems to be the Content-Type, as application/octet-stream

 

When I try to run the test from SoapUI Pro TestCase, I still get the error "An error occurred while processing your request.".

Question is, what am I setting up incorrectly in REST Method that causes the error? I'm certain this is a REST POST, and not a SOAP Request?