you have a large list, say 30,000 items, you will not be able to upload to SharePoint.
This blog post will show you how to resolve the issue using a command.
Go to Site Setting to upload a large list. In this example, I will upload
a list that contains 30,000 items. Click OK.
The following error message will
be displayed: “The request exceeded the 50 megate size limit defined the
Open a Command Prompt and run as Administrator on each SharePoint server.
Enter the following command: %windir%system32inetsrvappcmd set config -section:requestFiltering
You will receive a confirmation message after applying the
Return to the Site
Setting to upload the list again.
You have successfully uploaded the list.