Error code 4503
Issue: When trying to install a firmware image via TP-Link WebGUI, I get the following error:
Error code: 4503 The uploaded file was not accepted
Root cause: ? 
Solution: Try TFTP installation instead of via OEM GUI.
Issue: When trying to install a firmware image via TP-Link WebGUI, I get the following error:
Error code: 4503 The uploaded file was not accepted
Root cause: ?
Solution: Try TFTP installation instead of via OEM GUI.