When FME Server is configured to use SSL for client-server communication, workspaces registered to the Notification Service may not run.
This issue is caused by security rules imposed by the Apache Tomcat application server that runs the Notification Service. The server rejects the self-signed certificate that was created when SSL was configured on the application server.
On the machine where FME Server is installed, run the following Java keytool command:
keytool -import -v -trustcacerts -alias server-alias -keystore "%JAVA_HOME%\jre\lib\security\cacerts" -file <your self-signed certificate> -keypass <key password> -storepass <keystore password>
This command imports the untrusted certificate into the FME Server database and instructs the web application server to make an exception for it.