Exception: You cannot access body after reading from request's data stream

Use request.data instead of request.body.

request.data does not read the data stream again.

The error You cannot access body after reading from request's data stream will be triggered on a request if (1) that request method is POST, (2) that request's POST dictionary is accessed in middleware, in either process_request or process_view and (3) within the view function, request.body is accessed. It is on (3) that the error will be raised, even though the real cause of the bug is (2).

In order to resolve the error, you need to examine your middleware for where it accesses request.POST and modify it such that it doesn't access request.POST anymore.

The Django docs say that middleware should not access request.POST, and this is one consequence of ignoring that recommendation.

Also check out this Django ticket on the issue, which includes the note:

[M]iddleware that hits request.POST should (usually) be considered a bug. It means that the view will be unable to set any custom upload handlers, perform custom parsing of the request body, or enforce permission checks prior to file uploads being accepted.

Adding to Adam Easterling's answer it is worth noting that Django itself 'violates' the hint of not using request.POST in middleware:

The CsrfViewMiddleware class can be considered an exception, as it provides the csrf_exempt() and csrf_protect() decorators which allow views to explicitly control at what point the CSRF validation should occur.

Which does not sanitilize the violation IMO