cannot login - Invalid Login: URL/Server has errors

[risros]

Android client reports:
Invalid Login: URL/Server has errors

Notes version 2.0.2

owncloud log:
{"reqId":"tex31LKG4zNPWD6jANnK","remoteAddr":"5.5.5.5","app":"PHP","message":"A session had already been started - ignoring session_start() at \/usr\/share\/nginx\/html\/lib\/private\/Session\/Internal.php#98","level":0,"time":"April 11, 2017 20:50:58","method":"GET","url":"\/index.php\/apps\/notes\/api\/v0.2\/notes","user":"--"} {"reqId":"tex31LKG4zNPWD6jANnK","remoteAddr":"5.5.5.5","app":"index","message":"Exception: ","level":3,"time":"April 11, 2017 20:50:59","method":"GET","url":"\/index.php\/apps\/notes\/api\/v0.2\/notes","user":"risros"} {"reqId":"tex31LKG4zNPWD6jANnK","remoteAddr":"5.5.5.5","app":"PHP","message":"hash_equals(): Expected user_string to be a string, null given at \/usr\/share\/nginx\/html\/lib\/private\/Log.php#274","level":3,"time":"April 11, 2017 20:50:59","method":"GET","url":"\/index.php\/apps\/notes\/api\/v0.2\/notes","user":"risros"}

Happens on android client and iOS client.
Worked before I upgraded php to php56w
OS: CentOS 7 / nginx 1.10.2