The most common reason that MATLAB will continuously prompt you for activation is that due to limited user permissions, administrator credentials were used to activate. As a result the license file is stored under the administrator account.
You must have permission to access the license folders to resolve this issue. Individual licenses, these files are placed in a folder specific to your Login Name on the system. License files for all other license types are located in the licenses folder within the MATLAB installation directory.
See the appropriate section for your license type and operating system to access the directory where your license files are stored.
If the license folders are empty, then the MATLAB activation client wrote license file to another account. To resolve the issue, activate MATLAB manually through the License Center using the instructions in the following article.
How do I activate MATLAB without an internet connection?
Then place the license file in the following locations depending on your license type:
Designated Computer, Concurrent, Network Named User
*Windows: *C:\Program Files\MATLAB\R20XXx\licenses
Mac: License files are stored inside the MATLAB application package.
Right click, CTRL-click, or two-finger click on the MATLAB icon in your Applications folder and select "Show Package Contents."
In the folder that opens up, open the "licenses" folder to see your license files.
If you have an Individual license type, or DO NOT have write permissions to the directories above, place the license file in these directories.
Mac: /Users/$USER/Library/Application Support/MathWorks/MATLAB/