Steps to Reproduce: - open browser & portal
- sign in & edit layout
- edit banner portlet - add some invalid value (e.g. url to some image) & save (it's successfully saved)
- close browser
- open browser & portal - you can't access portal anymore
project_key: JBEPP

When you edit banner portlet with invalid value, close & open browser -> you are not able to access portal.
With each refresh it takes another database connection and after 20 attempts you end up with:

13:20:10,748 ERROR [JDBCExceptionReporter] Unable to get managed connection for gatein-idm; - nested throwable: (javax.resource.ResourceException: Unable to get managed connection for gatein-idm)

I'm also attaching thread dump where you can see that 20 threads are running in following classes:
at java.util.HashMap.get(HashMap.java:300)
at org.exoplatform.resolver.ApplicationResourceResolver.getResourceResolver(ApplicationResourceResolver.java:70)
at org.exoplatform.webui.application.WebuiRequestContext.getResourceResolver(WebuiRequestContext.java:184)

I think there is problem with while loop in WebuiRequestContext.getResourceResolver method.

Issue was found by automated tests where logo portlet should be edited on dashboard, but edit layout is broken and portal layout is used instead of dashboard layout.
After described steps, cpu is running almost on 100% and it caused my laptop to turn-off due to overheat few times.