Docs are not saving Portal Error

I have a data field and attach field in a webform,after entering data and attaching document,it shows

Error: Document has been modified after you have opened it (2017-09-20 14:42:25.969028, 2017-09-20 14:42:26.293139). Please refresh to get the latest document.

I need to refresh every time to save the data,is there any solution

Is it a standard web form or custom?

I don’t think anything has changed WRT web forms recently.

Steps to replicate?

Thanks for the reply it is now resolved,but I have an issue with WWW folder

in that filename.html is working but the is not compiling while I try to render that page hence I cant able to get server side data