FlexNet licensing error -8: Invalid (inconsistent) license key
This error message indicates that you have a corrupted license file.
This could be accidental, or because you have tried to edit the license file.
Only the comment sections of Arm tools licenses can be edited (those lines starting with a # character). You can not edit any other part of the file without it becoming invalid.
To fix this, download a fresh copy of the license file from your account on the Arm web licensing portal and then follow the instructions in the FAQ for installation of a node-locked license.