The report server installation is not initialized. (rsReportServerNotActivated) in AX 2012
AX: AX 2012 R3
OS: Windows Server 2012
SQL: SQL 2014
This can be easily fixed by opening the Keys table in the Report Server database in SQL and deleting the row that contains the name of the old Reporting Services server.
Alternatively, you can create a new Reporting Services database which is fast and easy.
Happy AX Infra!
Thanks & Regards,