I'm getting such an issue with opencms older version 8.5, have tried reimporting the war file but still end up with that issue in the logs and error 500 on the pages.
ERROR [ org.opencms.main.OpenCmsCore:1991] Unknown resource type id 807 requested. OPENCMS
104 views Asked by Leslie Murungi At
1
Later i was able to crack it. Noticed that the error generated from CmsResourceManager.java. And reason being is because this particular class expects certain information from an XML file. https://documentation.opencms.org/javadoc/core/org/opencms/file/types/CmsResourceTypeUnknown.html
In this case the modules file. Always located in /WEB-INF/config/opencms-modules.xml If this file is empty or a certain module is missing then the error will occur, by default its filled with all opencms default modules that enable the opencms to work. Hence for a crashing app, one needs to run a separate installation of opencms which fully loads or from any backup of the same version of opencms. Copy the content from modules file and paste in the same file in the crashing app.