Recently this happened to me around 3 times, with seemingly random moments causing it. As soon as click on any page or any layout, the radzen screen goes blank. My client folder has been deleted, so it has no custom modules on that side. And I haven't editted the meta files at all.
[2019-09-19 12:13:05.063] [info] Update for version 2.23.0 is not available (latest version: 2.23.0, downgrade is disallowed.
[2019-09-19 12:15:57.724] [info] Checking license...
[2019-09-19 12:15:59.276] [info] License check result: false
[2019-09-19 12:15:59.478] [info] Checking for update
[2019-09-19 12:16:00.208] [info] Update for version 2.23.0 is not available (latest version: 2.23.0, downgrade is disallowed.
[2019-09-19 12:17:47.328] [info] Checking license...
[2019-09-19 12:17:48.356] [info] License check result: false
[2019-09-19 12:17:48.359] [info] Checking for update
[2019-09-19 12:17:49.081] [info] Update for version 2.23.0 is not available (latest version: 2.23.0, downgrade is disallowed.
[2019-09-19 12:19:02.893] [info] Checking license...
[2019-09-19 12:19:03.952] [info] License check result: false
[2019-09-19 12:19:03.956] [info] Checking for update
[2019-09-19 12:19:04.661] [info] Update for version 2.23.0 is not available (latest version: 2.23.0, downgrade is disallowed.
[2019-09-19 12:25:54.378] [info] Checking license...
[2019-09-19 12:25:56.004] [info] License check result: false
Meanwhile I found out that uninstalling and installing again seems to fix it, so installation corruption somehow?