PHP functions not working in bitcoin JSON-RPC version 16 (bitcoin-cli is working properly)
getinfo was removed from Bitcoin Core 0.16. Use getblockchaininfo, getnetworkinfo, getmininginfo, or getwalletinfo depending on what you actually need. A mapping of each getinfo field to its replacement can be found here: https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.14.0.md#getinfo-deprecated