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:
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:
-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.