I urge you to run a cleanup program once a month. However, in general terms, all of those specs sound fine.
Do you happen to know if the error message arises when you calibrate the laptop screen? Or is it only the external?
No, once that jpeg damage is done, it's done. You have to start again from the raw image.
PLEASE read: https://www.damiensymonds.net/2010/02/trash-those-jpegs.html
Well, if your external screen was perfect, then yes, you'd want them to match Since it's not perfect, I held high hopes for the laptop one
Let's go back to that 6500 error thing. I need you to do this.
Oh!!!!! I didn't know this! I should have looked at your sidebar, and I would have figured it out.
Can you confirm you have the external screen set to "Extend" not "Duplicate" in the Display Control Panel?