your V.3.80b version J-Falsh need a license key to run some funcations such as eraes chip .... the olders version (V.3.80a) didn't need it. How can I get a key ?
the license system was not changed between V3.80a and V3.80b. Maybe you have one J-Link with built-in license and another one without license. Are you sure that you have used the same J-Link with both versions ?