# Compatibility notes
Depending on how your EventStoreDB instance is configured, some of the features might not work. On this page, you can find some notes about features being not available because of some options are set or not set accordingly.
|Connection for TCP clients||External TCP is disabled by default. You need to enable it explicitly by using the |
|Connection without SSL or TLS||EventStoreDB 20.6+ is secure by default. Your clients need to establish a secure connection, unless you use the |
|Authentication and ACLs||When using the |
|Projections||Running projections is disabled by default and the |
|AtomPub protocol||In 20.6+, the AtomPub protocol is disabled by default. If you use this protocol, you have to explicitly enable it by using the |
|Stream browser||The stream browser feature in Admin UI depends on the AtomPub protocol and also gets greyed out by default. You need to enable AtomPub (previous line) to make the stream browser work.|