Port busy on trying to open serial monitor

Development Tools IDE 1.x
1

I am able to load a program but whenever I try to open the serial monitor I get:

Error opening serial port 'COM15'. (Port busy)

I have a couple of different FT232 type USB to serial adapters and it does it on both. Also on an Uno board. All that I had no previous problems with.

This is a new install on my work computer. Windows 7, Arduino 1.6.8

Any suggestions will be appreciated.

2

Try installing Arduino IDE 1.6.9 or 1.6.5. Let me know if that doesn't solve the problem.

3

pert:
Try installing Arduino IDE 1.6.9 or 1.6.5. Let me know if that doesn't solve the problem.

Just wanted to let it be known that the problem went away after I installed 1.6.9.

Thanks.