I fixed this error by using the incognito mode of Chrome

Yes meself2, I searched on Google and saw that in about six months ago, some people also met the similar problem. But I didn't see how they solved.

Hi,
Today, I also could not submit my documents to Inis Online to renew my IRP.
I tried on Firefox, Microsoft Edge and Chrome But All of them were not successful.
My documents are .pdf and .jpg and less than 5MB.