1. Delete instance.out file  in /opt/zpa/bin/ directory               
 rm /opt/zpa/bin/instance.out
#Logical name of your application
    application.name=PHP-Application  | 
            3. Restart the PHP agent service in /opt/zpa/bin using the following command                  
 sh run.sh restart
For Windows,
Delete instance.out file in the APM Insight installation directory.
By default, this is found in C:\Program Files (x86)\APM Insight PHP Agent\zpa\bin\
Edit apminsight.conf file in the installation directory.
Default location C:\Program Files (x86)\APM Insight PHP Agent\zpa\conf\
      3. Restart APM Insight PHP Agent windows service.