With the Serial Monitor open in a running sketch, I can not upload another sketch without first closing the running sketch. I get the following errors:
avrdude: ser_open(): can't open device "\.\COM4": Access is denied.
Upload error: Error: 13 INTERNAL: Failed uploading: uploading error: exit status 1
In the previous versions of the IDE, I could have one sketch running with Serial Monitor open, and upload another sketch when I had the data I needed from the first sketch. However, in 2.0 beta, it's not possible if Serial Monitor is open in a running sketch., it results in a failed upload with the above error messages.
The only way I can upload the second sketch is to completely close the first sketch.
This is most annoying, and I've had to go back to the previous version of the IDE until this issue with 2.0 beta is corrected.