new to this, here's whats happening so far (Arduino Leonardo) windows 10 v.1909
i was able to upload the BareMinimum once. after that i get an error message and cant upload it again. any help appreciated. error message:
Sketch uses 3462 bytes (12%) of program storage space. Maximum is 28672 bytes.
Global variables use 149 bytes (5%) of dynamic memory, leaving 2411 bytes for local variables. Maximum is 2560 bytes.
processing.app.debug.RunnerException
at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:152)
at cc.arduino.UploaderUtils.upload(UploaderUtils.java:77)
at processing.app.SketchController.upload(SketchController.java:732)
at processing.app.SketchController.exportApplet(SketchController.java:703)
at processing.app.Editor$UploadHandler.run(Editor.java:2047)
at java.lang.Thread.run(Thread.java:748)
Caused by: processing.app.SerialException: Error touching serial port 'COM4'.
at processing.app.Serial.touchForCDCReset(Serial.java:107)
at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:136)
... 5 more
Caused by: jssc.SerialPortException: Port name - COM4; Method name - openPort(); Exception type - Port busy.
at jssc.SerialPort.openPort(SerialPort.java:164)
at processing.app.Serial.touchForCDCReset(Serial.java:101)
... 6 more