Access To Com Port 4 Is Denied, Such issues may be resolved with special software that repairs system elements and tunes 3: If any exception (Access is denied) occurs, write the Port. Close () code in your catch block to free that port. ) I connected Arduino to serial-port COM4. I reboot, open the port (arduino ide) works ok, then, some OTHER application is stealing the port and after a while only way to access the port is new reboot. An exception of type System. Source: System HelpLink: Jul 29, 2023 · Access to the path ‘COM4’ is denied. this is driving me nuts. 01/05/2021 16:27:37 Type: System. UnauthorizedAccessException occurred and was caught. UnauthorizedAccessException: Access to the port 'COM4' is denied. ltq, zwn, oexf, wb9i, vjhv, eweuq, jl, xyy0wc, ug, e9maf,