Licence expired - New licence purchased but service fails so cannot apply

Firewall analyzer has been down for some time but I have just spotted it due to needing to renew the licence.
The drive the application is on had filled up but has now been extended.

The wrapper log shows the following error on service launch:
STATUS | wrapper | 2016/06/21 16:53:44 | --> Wrapper Started as Service
STATUS | wrapper | 2016/06/21 16:53:44 | Java Service Wrapper Professional Edition 64-bit 3.5.15
STATUS | wrapper | 2016/06/21 16:53:44 |   Copyright (C) 1999-2012 Tanuki Software, Ltd. All Rights Reserved.
STATUS | wrapper | 2016/06/21 16:53:44 |     http://wrapper.tanukisoftware.com
STATUS | wrapper | 2016/06/21 16:53:44 |   Licensed to Zoho Corporation Pvt. Ltd. for ManageEngine Firewall Analyzer
STATUS | wrapper | 2016/06/21 16:53:44 |
STATUS | wrapper | 2016/06/21 16:53:45 | Launching a JVM...
INFO   | jvm 1    | 2016/06/21 16:53:45 | WrapperManager: Initializing...
INFO   | jvm 1    | 2016/06/21 16:53:45 | Starting Server from location: E:\ManageEngine\Firewall
INFO   | jvm 1    | 2016/06/21 16:53:45 | ERROR CODE : 535
INFO   | jvm 1    | 2016/06/21 16:53:45 | Invalid License File

Firewall Analyzer is installed on a 64 bit Windows 2008 R2 server.

I was not too concerned about historical data so have run the reinitializedb.bat in case the issue was corrupted DB.
I have also tried renaming the existing ZOHOCorpAMS.xml file in the licence directory and copying in the new licence.

What's next?

Regards
Paul