We're currently running into an issue where the Liferay server will start to only show the license page (/c/portal/license) no matter what URL the user enters. This behavior continues until we restart the server. When the license screen is shown it shows the correct details of the development license that was installed and that is perfectly valid (and also just worked before and also after a restart). No error message is shown on the page or in the log file that we can directly relate to this problem.
This problem happened on the same server with 2 different development licenses (a new one was recently installed) and each time disappeared for a while after a restart just to come back at a seemingly random moment. So we can't really provide you with a reproducible scenario as we haven't been able to find one ourselves.