IIS also has a maximum request size that will need to be reset if you’re uploading documents larger than about 200kb.
1) Open IIS Manager by going to start > control panel > administrative tools. Right click on the server name > properties. Click on enable direct metabase edit. If this box isn’t checked you won’t be able to edit the metabase.xml file.
2) Open my computer. In the address bar put this and hit enter: %SYSTEMROOT%\system32\inetsrv
3) Find the metabase.xml file and open it with some kind of text editor
4) Search for the line that says AspMaxRequestEntityAllowed. Change that to your max file upload size.
5) Go back to IIS and uncheck direct edit metabase checkbox.