When uploading files on Mi-Forms Windows client, you may get this error when uploading forms with large files/images:

While this indicates that a generic HTTP level error occurred, if your form is large, it's possible this is caused by the server rejecting a large upload.

A way to fix this problem is to config IIS so that it has an increased max content upload size. In order to change the max content upload size, you must:

• Navigate to the proper IIS Server by opening the Internet Information Services (IIS) Manager
• Navigate into “FTP Request Filtering” in the FTP Section
  
• Click the “Edit Feature Settings” link on the right side “Actions” panel
  
• Modify the “Maximum Content Length” to be as big as the files that need to be uploaded