Upload error on form submission

I don't understand,how fix this problem, pls help me 

I have checked your form and found that it works fine at the moment. 

I could not find any upload file field in your form; however, upon reviewing the changes history of your form I can see you have removed such field. 

Could be possible to add the field again to your form so we can test on it? 

We'll wait for your response. 

I add upload file fieldes, and error appeared again :(
https://form.jotformeu.com/70186322066351

I test submitted your form https://www.jotformeu.com/form/70186322066351 and even uploaded files. It was working just fine.

Please test again. Try also using a different browser perhaps the issue is on your browser only.

Let us know if issue still persist.