In order to enable detailed Log Level on the RHEV Manager for trouble shooting you can tune the below file and restart RHEV Manager Service .
Open the below file using a editor
C:\Program Files (x86)\Redhat\RHEVManager\Service\RhevManager.exe.config
Look for "Info" - you'll find the log level part. change "info" to "All", as the list there indicates
Restart the RHEVManager Service for the change to take effect by typing services.msc on the Start-->Run -->services.msc
Once you fixed the issue then change the log level back from "ALL" to "Info" and Restart the RHEVManager Service to avoid logging flooding more disk space.