When you launch Spotfire server UI configuration tool, it shows spinning(processing) symbol continuously and does not allow to load any configuration in UI config tool.
You may also not able to browse Spotfire server URL after restart of Spotfire server service.

The following error appears in Spotfire server logs(catalina.log  and server.log files) once you restart Spotfire server service :
-------------------------------- 
22-Feb-2019 00:00:58.096 SEVERE [localhost-startStop-1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: 
 org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Spotfire].StandardHost[localhost].StandardContext[/spotfire]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1141)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: com.spotfire.server.config.ConfigurationException: Invalid configuration property hierarchy
    at com.spotfire.server.config.ConfigurationPropertiesModel.validate(ConfigurationPropertiesModel.java:117)
    at com.spotfire.server.config.ConfigurationPropertiesModel.<init>(ConfigurationPropertiesModel.java:60)
    at com.spotfire.server.config.ConfigurationPropertiesImpl.<init>(ConfigurationPropertiesImpl.java:53)
    at com.spotfire.server.config.CloningConfigurationPropertiesImpl.<init>(CloningConfigurationPropertiesImpl.java:36)
    at com.spotfire.server.util.sql.DataSourceManager.<init>(DataSourceManager.java:93)
    at com.spotfire.server.lifecycle.SpotfireApplicationInitializer.initRootContext(SpotfireApplicationInitializer.java:151)
    at com.spotfire.server.lifecycle.SpotfireApplicationInitializer.onStartup(SpotfireApplicationInitializer.java:95)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:169)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5196)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 10 more
----------------------------------- 

Cause: 
The above error indicates that there is some issue with current Spotfire server configuration. Maybe it's corrupted or not valid.

All Supported OS

To resolve this issue, one need to set any of the last working Spotfire server configuration as current configuration for Spotfire server.

Follow below steps to list and import last working Spotfire server configuration:

- On Spotfire server machine, launch command prompt with "Run as Administrator"
- Browse to location "<Spotfire_server_install_Dir>/tomcat/bin" in command prompt.
Note: There is  change in folder structure post 10.3. Replace bin folder to spotfire-bin folder in above command.
- Run below command to list all Spotfire server configurations:
----------- 
config list-configs
-----------

Refer below link for more information about this command :
https://docs.tibco.com/pub/spotfire_server/10.1.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-747F858B-F62A-47D6-8566-7FA9A5624115.html

- From the listed configurations in above command, import last working configuration (provided one should know what was last working configuration) using below command:
-----------
config set-config 
-----------

Refer below link for more information about this command :
https://docs.tibco.com/pub/spotfire_server/10.1.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-D2764047-110D-4417-838F-33CA2BE570EB.html

- Once configuration is set using above command, restart the Spotfire server service to make the changes effective.
 

Not able to launch Spotfire server UI configuration tool with latest(current) configuration.

https://docs.tibco.com/pub/spotfire_server/10.3.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-747F858B-F62A-47D6-8566-7FA9A5624115.html
https://docs.tibco.com/pub/spotfire_server/10.3.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-D2764047-110D-4417-838F-33CA2BE570EB.html