I've just applied an Academic License and waiting for the approval.
Since I have my laptop with both Windows 10 and Ubuntu Linux I would like to ask if I can use one license for both systems.
And what should I do with the instant JChem if I make a upgrade of my Linux system?
(There is usually a half year or one year upgrade cycle for Linux systems ...)
Can I use the same License file after reinstall my linux system?
Sorry for being a bit late with the answer; and as far as I know part of your request is already solved, since you received your academic license.
In the confirmation email you could have found a link pointing to the My Licenses page, where you can see all of your licenses (after logging in), including the academic license as well. From this location you can download and install the license to any machines, and as far as it is your own machine, you will be able to repeat it several times. So, no worries about the Linux updates.
I hope that helped,