Occasionally, we have seen this after upgrade/updates. I don't know why it goes bad after an update, but the quick resolution was to delete and recreate it. Take screen grabs of what you have before you delete it.

I have seen this when Java magically updates itself on the Tomcat host(s). The fix is to uninstall Java and then re-install the latest Java and confirm your Java options (path, memory, etc). It seems Java on Windows doesn’t always respect the update setting which you have defined. I had to neuter Java update in the registry to stop this from happening.

Thanks guys - it was the SSL cert for whatever reason within LDAP needed re-uploading and restarting tomcat afterwards.