Docusign rest api composite template error - json

Question

I've made composite templates and had them working before, but I'm suddenly getting an error and have no idea why this is causing an issue. Here's my request:
POST https://demo.docusign.net/restapi/v2/accounts/356019/envelopes HTTP/1.1
Host: demo.docusign.net
X-DocuSign-Authentication: <DocuSignCredentials><Username>test#gmail.com</Username><Password>*****</Password><IntegratorKey>****</IntegratorKey></DocuSignCredentials>
Content-Type: multipart/form-data; boundary=MY_BOUNDARY
Accept: application/json
Content-Length: 807319
Expect: 100-continue
Connection: Keep-Alive
--MY_BOUNDARY
Content-Type: application/json
Content-Disposition: form-data
{
"emailSubject": "Please Docusign this",
"emailBlurb": "This is a test... Also sign this form",
"enableWetSign": "true",
"status": "sent",
"compositeTemplates": [
{
"inlineTemplates": [
{
"sequence": "1",
"recipients": {
"signers": [
{
"email": "test#gmail.com",
"name": "test",
"recipientId": "1"
}
]
}
}],
"document":
{
"documentId": "1",
"name": "test0",
"fileExtension": "pdf"
}
}
]
}
--MY_BOUNDARY
Content-Type: application/pdf
Content-Disposition: file; filename="test0.pdf"; documentid="1"
<pdf bytes here>
--MY_BOUNDARY--
I have this working with server templates, but it seems like anything that requires the document object gives me a bad request. The request I'm getting is:
Request Error: BadRequestDocuSign Error: {
"errorCode": "UNSPECIFIED_ERROR",
"message": "the document is corrupt, rebuilding failed"
}
I've read the pdf bytes in another program and have successfully created a pdf from it, so I'm not sure what could be causing this issue. Does anybody know what the problem may be? Thank you for your time.