After applying Maintenance for Output Management Web Viewer 12.1, the build number remains the same.
The log for the install of the maintenance, located in the CA_OM_Web_Viewer/uninstaller/Logs directory showed the following error:
ERROR - build.xml:114: Error while expanding /tmp/629488.tmp/CAOMWebViewer12.war
Output Management Web Viewer 12.1 for Linux or USS
There is a lack of temp space ...specifically in the system default /tmp folder
The System Properties you need to set are: -Dlax.nl.env.iatempdir and java.io.tmpdir
Here is an example:
java -Dlax.nl.env.iatempdir=<Desired location>/tmp -Djava.io.tmpdir=<Desired location>/tmp -jar CA_OM_WebViewer_12_Updt.jar
Where <Desired location>/tmp is your new temporary folder with at least 500MB (Update installer) of free space.