[Plugin: Contact Form 7] upload image file field causing error

My form works fine until I add the upload file field. When i press send the arrow just spins around. I have checked folder permissions, the uploading fiel destination in wordpress and the image I am testing this with is very small. Does any have any idea where I should start?

Thanks very much in advance

https://www.ads-software.com/extend/plugins/contact-form-7/