Next error messages is obtained when running the upgrade.

unzipping WS/com.wily.ui.guiffy.nl1_10.7.0.jar from patch.zip to /opt/Introscope10.7.0.45/ws-plugins/com.wily.ui.guiffy.nl1_10.7.0.jar 
creating directory structure /opt/Introscope10.7.0.45/hotfix/10.7.0-HF29/bin 
moving file /opt/Introscope10.7.0.45/bin/WatchDog.jar to /opt/Introscope10.7.0.45/hotfix/10.7.0-HF29/bin/WatchDog.jar 
unzipping EM/WatchDog.jar from patch.zip to /opt/Introscope10.7.0.45/bin/WatchDog.jar 
Copying /opt/Introscope10.7.0.45/Introscope_Enterprise_Manager.lax to /opt/Introscope10.7.0.45/hotfix/10.7.0-HF29/Introscope_Enterprise_Manager.lax 
creating directory /opt/Introscope10.7.0.45/work 
editing properties file /opt/Introscope10.7.0.45/Introscope_Enterprise_Manager.lax 
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/commons/configuration2/builder/FileBasedConfigurationBuilder : Unsupported major.minor version 52.0 

Application Performance Management (APM) installer to upgrade to SP3 require Java 1.8.  
The issue occurs because the installer is not finding Java 1.8 but another version.

APM 10.7 GA
CentOS 7 

1. Check  what is the Java version used by the system with the command line 
     > java -version
   
2. If more than one Java version is installed on the server, you may select the one in <EM_HOME> with next command line

     > sudo alternatives --config java

     From the list select the number that corresponds to the Java installed under <EM_HOME>
     This will change the default Java used by the System.

3. Once you make sure "java -version" return the correct JRE, re run the installer.
 

Product Documentation.

https://docops.ca.com/ca-apm/10-7/en/upgrading/upgrade-components/upgrade-the-enterprise-manager