I have written a very simple portlet based on "Explore The Power of ZK + Liferay Integration" guide and was able to deploy my portlet in Liferay.
When I load the Liferay page the first time, the portlet does show up as expected. When I refresh the page, either force a reload or change the language for the portal, the portlet does no longer display. I simply see a popover with the "Processing ..." message and a spinning wheel cursor. All other portlets in the page remain functional.
From what I could see, this problem seems to only occur with Safari. I have tested with the latest releases of Firefox and Google Chrome and the problem does not occur. When I remove the ZK portlet from the page everything is working as expected.
I have attached a screenshot of the portlet showing the Processing ... message and a project export from Eclipse for the portlet.
In the developer tools in Safari I don't see anything wrong (no error message).
Do you have any knowledge about this kind of problem.
Many thanks in advance for your support.