Bug #8603

could not open port COM4: [Error 5] Access is denied.

Added by Ian Ralston about 1 month ago. Updated about 1 month ago.

Status:Closed Start date:12/29/2020
Priority:Normal Due date:
Assignee:- % Done:


Target version:-
Chirp Version:daily Platform:Windows
Model affected:USB to Serial cable


Whenever I try to program my UV-5R I get the above error. Port COM4 is the only available port I see under the drop-down menu.


Updated by Jim Unroe about 1 month ago

  • Status changed from New to Feedback

My guess is that COM port listed in CHIRP is either not the programming cable or a device driver that is compatible with the USB-to-Serial chip in the programming cable has not been installed in your computer.

While in Windows Device Manager, remove the programming cable from the computer. Does the COM4 entry get removed from the list? If COM 4 remains, some other device is assigned COM4. If COM4 disappears and appears when the programming cable is removed and plugged in, then COM4 is the programming cable but you likely have driver issues. While still in Device Manager, double-click the entry for the programming cable to open the port's properties. Click the "Driver" tab to see the driver details. If it shows "Prolific", then the device driver auto installed by Windows is not compatible. You must either download, install and select and older device driver that is compatible or purchase another programming cable with a different brand of USB-to-Serial chip (FTDI, Silicon Labs, WCH, etc.).

Visit the miklor.com USB Cable Drivers page for more details.


Updated by Bernhard Hailer about 1 month ago

Please let us know whether you could resolve your issue. Thanks!

Updated by Bernhard Hailer about 1 month ago

  • Status changed from Feedback to Closed
  • Model affected changed from (All models) to USB to Serial cable

No more feedback by submitter.

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