Confluence Server down - Root exception is java.lang.ClassNotFoundException: Cannot instantiate class: com.sun.jndi.ldap.LdapCtxFactory confluence from bundle [com.atlassian.plugins.rest-atlassian-rest-module]

Hello everyone,

Recently multiple times Confluence server is crushing with this message shown on the picture:

What can cause this problem? Is it something maybe connected with plugins or maybe something totally different?

Any help or thought is useful.

Thank you