F5 x-chunk

sorry for the simplicity in this but i keep getting a 'http request body unparsed payload'. it's a user file upload. multiple types, pdf zip txt. theres no content type in the post and i tried a do nothing for multipart/form-data under the uri. there's nothing that should be conflicting w it. the xchunk is identifying the file type uploaded but theres not much to go off of. i just have a list of individual attack sigs to tune for on the user end. kinda lost.

any help is appreciated 

TIA