Channel Form Matrix File Upload

Question

ExpressionEngine 2.8.1
Matrix 2.5.10

I'm using Channel Form to allow users to update their own entries on our website. I'm using a Matrix field to allow them to upload documents (mostly PDFs). When the form gets submitted the text cell in the Matrix field saves just fine, but the file cell is not being uploaded or saved.

I thought the workflow plugin I was using was hijacking file uploads, but it turns out after uninstalling it that file uploads still did not work.

I did see that a similar sounding issue was fixed in the latest version (which I have installed), but the issue is still occurring for me. This same thing happens on Grid fields as well. I have double-checked File Upload permissions and folder permissions. Regular file uploads work fine (I have another field in the entry that just uploads a single file).

Any suggestions on how to fix this?

UPDATED

I updated to 2.8.1 hoping that there was a bug that was fixed. I've found two places where this is considered a bug, but they've been reported as fixed. For me, this is still happening. I wish there were some error log that could point me in the right direction.

Answer 1

The bugs mentioned in my question have been, in fact, fixed. The problem I was having was that any file that wasn't an image was being caught by EE's Apply XSS Filtering to Uploaded Files Setting. This setting is a bit overzealous and refused anything that wasn't an image. Turning this off will allow uploading of PDFs and other files within Grid and Matrix fields.