KB Article #177471
Upgrade Installer 4.5.0 SP4 to 4.8 or 4.9 failed
Problem
Upgrade Installer 4.5.0 SP4 to 4.8 or 4.9 failed with Malformed \uxxxx encoding error
Extract of install.log :
2015-10-12 17:21:05 ERROR Malformed \uxxxx encoding.
Resolution
Go to the Configuration folder of your Synchrony installation.
Edit all *.properties file and change :
"\u" -> "\\u"
"\U" -> "\\U"