AF 10.7.0 HF 12 unable to install on EM

Products

• APP PERF MANAGEMENT
• CA Application Performance Management Agent (APM / Wily / Introscope)
• CUSTOMER EXPERIENCE MANAGER
• INTROSCOPE

Issue/Introduction

Applied APM 10.7.0 HotFix 12 in the Development environment but the installation failed with errors on both MOM and EM instances.

Log messages:
# Copyright (c) 2018 CA. All Rights Reserved. in config/IntroscopeEnterpriseManager.properties
replacing # URL that points to the root of the ACC REST API with # Command Center URL used for navigating to Command Center from the ATC UI main
# navigation. Link will be hidden if URL value is empty. Default value is empty.
# It's also URL that points to the root of the ACC REST API in config/IntroscopeEnterpriseManager.properties
Error while executing the scenario
java.lang.IllegalArgumentException: The validated string is empty
        at org.apache.commons.lang.Validate.notEmpty(Validate.java:321)
        at org.apache.commons.lang.Validate.notEmpty(Validate.java:339)
        at com.ca.fix.command.ReplaceInFile.<init>(ReplaceInFile.java:54)
        at com.ca.fix.command.ReplaceInFile.<init>(ReplaceInFile.java:47)
        at com.ca.fix.HotfixBase.replaceInFile(HotfixBase.java:169)
        at com.ca.fix.apm.hotfix.Hotfix.emHotfix(Hotfix.java:555)
        at com.ca.fix.apm.hotfix.Hotfix.scenario(Hotfix.java:120)
        at com.ca.fix.HotfixBase.apply(HotfixBase.java:89)
        at com.ca.fix.HotfixBase.execute(HotfixBase.java:61)
        at com.ca.fix.apm.hotfix.Hotfix.main(Hotfix.java:80)
Rolling back the scenario
reverting replace of # URL that points to the root of the ACC REST API with # Command Center URL used for navigating to Command Center from the ATC UI main
# navigation. Link will be hidden if URL value is empty. Default value is empty.
# It's also URL that points to the root of the ACC REST API in config/IntroscopeEnterpriseManager.properties
reverting replace of # Copyright \(c\) 2018 CA\. All Rights Reserved\. with # Hotfix 10.7.0-HF12

Cause

Comments removed manually from IntroscopeEnterpriseManager.properties files installed with APM 10.7.0 GA

Environment

APM 10.7.0 HF 12

Resolution

This is the text in IntroscopeEnterpriseManager.properties in 10.7.0 CHF#12: 
############################################################################### 
# ACC Connection Configuration 
############################################################################### 
# Command Center URL used for navigating to Command Center from the ATC UI main 
# navigation. Link will be hidden if URL value is empty. Default value is empty. 
# It's also URL that points to the root of the ACC REST API 
#introscope.appmap.acc.rest.base=http://acc_host:acc_port/apm/acc 


And this is the text in 10.7.0 GA: 
############################################################################### 
# ACC Connection Configuration 
############################################################################### 
# URL that points to the root of the ACC REST API 
#introscope.appmap.acc.rest.base=http://acc_host:acc_port/apm/acc 

Do not delete this comment section in the configuration file before installing HF 12.. The hotfix is trying to replace the comments only,  If needed, please attempt to reconstruct the configuration file so if these lines are there the HotFix is not reverted.