There's a known problem in the API Runtime installer (NOT the EV Serverinstaller) which can prevent some Managed assemblies from being properly registered for COM interop. This can be problematic especially if you up-or downgrade, as the assembly versions written as part of the COM registration won't be updated, so you will get errors at runtime.
This script can be run against versions from 9.0.3 onwards. It will re-register both unmanaged and managed files and report on errors.
The script includes checks for processor architecture and UAC elevation and will re-launch itself in the correct mode if needs be.
This script should not be run on an EV Server, it is only intended to be run on a standalone server which is just running the API Runtime. For example, when a 3rd party application developed by a STEP partner which integrates with Symantec Enterprise Vault needs to run on a server other than the EV Server.
If you have COM registration problems on the EV Server and need to re-register files, the server installer writes a file called FileReRegister.bat, which you can run (from an elevated cmd prompt if you have UAC enabled) to re-register\repair any broken file registrations.