PMC or Agent installation error: An internal error occurred (error code: 20)

Problem

Shortly after double-clicking on the PMC or Agent installer, the process terminates with the following error:

CODE

An internal error occurred (error code: 20)
Log: C:\Users\USER\AppData\Loal\Tempi4j_nlog_X.log

Diagnosis

Examining the log file from the error message shows the following entries at the bottom:

CODE

-r "jre\lib\charsets.jar.pack" "jre\lib\charsets.jar"
could not create unpack process

The installers are unable to initialize and execute because an anti-virus or another security software is preventing the execution of a process in the temp directory.

Solution

The solution is to temporarily stop any anti-virus or security software that may interfere with the installer's unpack process into the temp directory.