Just as the title says, I installed Smart Security v18.104.22.168 in Windows XP the other day. I exported my version 4 configuration to an XML file first, uninstalled v22.214.171.124, installed v126.96.36.199 and tried to import the configuration file. It didn't work. I got a pop-up box telling me there was an error with the configuration file. I went back to the old v188.8.131.52 and it imports the configuration file with no problem. So the file itself is not corrupt. It's just unusable to version 5. Is a version 4 export supposed to be compatible as a version 5 import? I've used ESS for several years now and the configuration file always used to be transportable to newer versions. Has that changed?