When running the AgentInstall.msi provided with agent package upgrade or agent hotfix, you get the following error:
Another version of this product is already installed. Installation of this version cannot continue.
To configure or remove the existing version of this product, use Add/Remove Programs on the Control Panel.
Agent hotfix or upgrade are provided in AgentInstall.msi package. Using the installation command:
msiexec /i AgentInstall.msi /q INSTALLDIR="C:\Program Files\Manufacturer\Endpoint Agent\" ENDPOINTSERVER="hostname" SMC="smc.hostname" KEY="" SERVICENAME="EDPA" WATCHDOGNAME="WDP" ARPSYSTEMCOMPONENT="1" will return the error.
This command is included in the install_agent.bat provided with the package.
To solve this issue use the following command instead:
msiexec /i AgentInstall.msi /q REINSTALL=ALL REINSTALLMODE=vomus
NB: This command should ONLY be used for minor upgrades and patches. This means that it can only be used to hot fix an existing agent installation that is on the same maintenance pack level. It cannot be used to upgrade to a newer maintenance pack or major version. This is because the product code used by agent builds within the same maintenance pack level all use the same MSI product code.
When using the REINSTALL=ALL REINSTALLMODE=vomus parameters, be certain also that the MSI file name is the same as the file name that was used to install the previous version of the agent. Failing to do so will result in a cryptic 1603 failure, with a "return value 3" reference to an MSI filename that is different than the one you are using. As an example, the following agent failure came from an attempt to install a 15.5 MP2 hotifx on top of an existing 15.5 MP2 GA agent build using the following command:
msiexec /i AgentInstall-x64_15_5.msi /q REINSTALL=ALL REINSTALLMODE=vomus
but the original agent MSI file name was AgentInstall-x64_15_5MP2.msi:
MSI (s) (CC:DC) [11:49:43:682]: Note: 1: 2203 2: C:\temp\Data Loss Prevention 15.5 MP2 Hotfix 218\AgentInstall-x64_15_5MP2.msi 3: -2147287038
MSI (s) (CC:DC) [11:49:43:682]: Note: 1: 1316 2: C:\temp\Data Loss Prevention 15.5 MP2 Hotfix 218\AgentInstall-x64_15_5MP2.msi
MSI (s) (CC:DC) [11:49:43:682]: SECREPAIR: Error determining package source type
MSI (s) (CC:DC) [11:49:43:682]: SECUREREPAIR: SecureRepair Failed. Error code: 52449BE3820
Action start 11:49:43: ProcessComponents.
MSI (s) (CC:DC) [11:49:43:682]: Note: 1: 2265 2: 3: -2147287035
MSI (s) (CC:DC) [11:49:43:682]: Machine policy value 'DisableRollback' is 0
Action ended 11:49:43: ProcessComponents. Return value 3.