In your web.config file search for the
< readerQuotas
and change it to
<readerQuotas maxDepth="2147483647"
maxStringContentLength="2147483647"
maxArrayLength="2147483647"
maxBytesPerRead="2147483647"
maxNameTableCharCount="2147483647" />
This will allow you to upload 2GB file size. or If you just want to test your code then upload a image which is less than 16KB (default size).