On September 9th, 2020, NYU updated the license servers MATLAB communicates with for purposes of authentication. If MATLAB no longer launches for you, there's a good chance the license server strings you have on your computer need to be updated. Here's how to do that in Windows 10: 


Step 1: Log in the PC with a user account that has administrative privileges. 


Step 2: In File Explorer: 
navigate to: This PC -> Windows (C:) -> Program Files -> MATLAB -> (your version number here, e.g. R2017a) -> Licenses. 

For reference:

Step 3: Right click on: "network.lic" -> Open With -> More apps -> Notepad 


Step 4: Edit the following: 

replacing the entire string with the following: 

# NYU ITS matlab license servers - 09.09.2020
SERVER lm2.its.nyu.edu 27000
SERVER lm3.its.nyu.edu 27000
SERVER lm4.its.nyu.edu 27000
USE_SERVER

Step 5: Save your changes: 

File -> Save -> 

In the pop-up window: 


select the drop-down menu by "Save as type:" 

and select "All Files", then confirm your change: 

Step 6: Launch MATLAB, confirming the license error no longer appears. 

Note: If you get a permission denied error when attempting to save the file, do the following: 

Right click on: network.lic -> Properties -> Security -> 

In Groups or user names, select: 

then Edit -> and Modify permissions by clicking off the "Full Control" box: 
saving your changes. Then redo the steps outlined earlier. 

Thanks.