I checked the SD card, power supply and checked the wiki.
Nextcloud logs
{"reqId":"WhGsgH8AAQEAAAUr0F4AABUD","level":3,"time":"2017-11-19T16:08:32+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"index","method":"GET","url":"\/index.php\/apps\/files\/","message":"Exception: {\"Exception\":\"OCP\\\\Files\\\\NotFoundException\",\"Message\":\"\",\"Code\":0,\"Trace\":\"#0 \\\/var\\\/www\\\/nextcloud\\\/apps\\\/files\\\/lib\\\/Controller\\\/ViewController.php(131): OC_Helper::getStorageInfo('\\\/', false)\\n#1 \\\/var\\\/www\\\/nextcloud\\\/apps\\\/files\\\/lib\\\/Controller\\\/ViewController.php(160): OCA\\\\Files\\\\Controller\\\\ViewController->getStorageInfo()\\n#2 [internal function]: OCA\\\\Files\\\\Controller\\\\ViewController->index('', '', NULL, false)\\n#3 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(160): call_user_func_array(Array, Array)\\n#4 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(90): OC\\\\AppFramework\\\\Http\\\\Dispatcher->executeController(Object(OCA\\\\Files\\\\Controller\\\\ViewController), 'index')\\n#5 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/App.php(114): OC\\\\AppFramework\\\\Http\\\\Dispatcher->dispatch(Object(OCA\\\\Files\\\\Controller\\\\ViewController), 'index')\\n#6 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Routing\\\/RouteActionHandler.php(47): OC\\\\AppFramework\\\\App::main('ViewController', 'index', Object(OC\\\\AppFramework\\\\DependencyInjection\\\\DIContainer), Array)\\n#7 [internal function]: OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler->__invoke(Array)\\n#8 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/Route\\\/Router.php(299): call_user_func(Object(OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler), Array)\\n#9 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/base.php(1004): OC\\\\Route\\\\Router->match('\\\/apps\\\/files\\\/')\\n#10 \\\/var\\\/www\\\/nextcloud\\\/index.php(48): OC::handleRequest()\\n#11 {main}\",\"File\":\"\\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/legacy\\\/helper.php\",\"Line\":543}","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhGsgX8AAQEAAAUr0GEAABUW","level":3,"time":"2017-11-19T16:08:34+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"index","method":"GET","url":"\/index.php\/apps\/files\/","message":"Exception: {\"Exception\":\"OCP\\\\Files\\\\NotFoundException\",\"Message\":\"\",\"Code\":0,\"Trace\":\"#0 \\\/var\\\/www\\\/nextcloud\\\/apps\\\/files\\\/lib\\\/Controller\\\/ViewController.php(131): OC_Helper::getStorageInfo('\\\/', false)\\n#1 \\\/var\\\/www\\\/nextcloud\\\/apps\\\/files\\\/lib\\\/Controller\\\/ViewController.php(160): OCA\\\\Files\\\\Controller\\\\ViewController->getStorageInfo()\\n#2 [internal function]: OCA\\\\Files\\\\Controller\\\\ViewController->index('', '', NULL, false)\\n#3 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(160): call_user_func_array(Array, Array)\\n#4 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(90): OC\\\\AppFramework\\\\Http\\\\Dispatcher->executeController(Object(OCA\\\\Files\\\\Controller\\\\ViewController), 'index')\\n#5 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/App.php(114): OC\\\\AppFramework\\\\Http\\\\Dispatcher->dispatch(Object(OCA\\\\Files\\\\Controller\\\\ViewController), 'index')\\n#6 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/AppFramework\\\/Routing\\\/RouteActionHandler.php(47): OC\\\\AppFramework\\\\App::main('ViewController', 'index', Object(OC\\\\AppFramework\\\\DependencyInjection\\\\DIContainer), Array)\\n#7 [internal function]: OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler->__invoke(Array)\\n#8 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/Route\\\/Router.php(299): call_user_func(Object(OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler), Array)\\n#9 \\\/var\\\/www\\\/nextcloud\\\/lib\\\/base.php(1004): OC\\\\Route\\\\Router->match('\\\/apps\\\/files\\\/')\\n#10 \\\/var\\\/www\\\/nextcloud\\\/index.php(48): OC::handleRequest()\\n#11 {main}\",\"File\":\"\\\/var\\\/www\\\/nextcloud\\\/lib\\\/private\\\/legacy\\\/helper.php\",\"Line\":543}","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhGs1H8AAQEAAAUr0IwAAAYP","level":3,"time":"2017-11-19T16:09:56+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"GET","url":"\/index.php\/settings\/personal","message":"Cannot redeclare {closure}() (previously declared in \/var\/www\/nextcloud\/settings\/personal.php:257) at \/var\/www\/nextcloud\/settings\/personal.php#232","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhGtZn8AAQEAAAUr0MwAABYF","level":3,"time":"2017-11-19T16:12:23+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"GET","url":"\/index.php\/apps\/firstrunwizard\/wizard","message":"Cannot declare class , because the name is already in use at \/var\/www\/nextcloud\/apps\/firstrunwizard\/lib\/Controller\/WizardController.php#0","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhGtr38AAQEAAAUr0NkAAAIJ","level":3,"time":"2017-11-19T16:13:35+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"GET","url":"\/index.php\/settings\/personal","message":"Cannot redeclare {closure}() (previously declared in \/var\/www\/nextcloud\/settings\/personal.php:257) at \/var\/www\/nextcloud\/settings\/personal.php#232","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhGvKn8AAQEAAAUsFtAAAABW","level":3,"time":"2017-11-19T16:20:00+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"PROPFIND","url":"\/remote.php\/dav\/files\/ash\/","message":"Class 'Sabre\\DAV\\Node' not found at \/var\/www\/nextcloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Collection.php#15","userAgent":"Mozilla\/5.0 (Linux) mirall\/2.3.2 (Nextcloud)","version":"12.0.3.3"}
{"reqId":"WhGvO38AAQEAAAUr0PIAAAAN","level":3,"time":"2017-11-19T16:20:11+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"PROPFIND","url":"\/remote.php\/dav\/files\/ash\/","message":"Class 'Sabre\\DAV\\Node' not found at \/var\/www\/nextcloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Collection.php#15","userAgent":"Mozilla\/5.0 (Linux) mirall\/2.3.2 (Nextcloud)","version":"12.0.3.3"}
{"reqId":"WhGvaH8AAQEAAAUr0PUAAAAQ","level":3,"time":"2017-11-19T16:20:56+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"PROPFIND","url":"\/remote.php\/dav\/files\/ash\/","message":"Class 'Sabre\\DAV\\Node' not found at \/var\/www\/nextcloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Collection.php#15","userAgent":"Mozilla\/5.0 (Linux) mirall\/2.3.2 (Nextcloud)","version":"12.0.3.3"}
{"reqId":"WhHU@X8AAQEAAAUsF5QAAFEC","level":3,"time":"2017-11-19T19:01:14+00:00","remoteAddr":"86.161.75.144","user":"admin","app":"PHP","method":"GET","url":"\/index.php\/apps\/activity\/","message":"Cannot declare class OCA\\Activity\\Controller\\Activities, because the name is already in use at \/var\/www\/nextcloud\/apps\/activity\/lib\/Controller\/Activities.php#34","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhJB238AAQEAAAUsF7AAAABI","level":2,"time":"2017-11-20T02:45:47+00:00","remoteAddr":"198.20.69.74","user":"--","app":"core","method":"GET","url":"\/","message":"Trusted domain error. \"198.20.69.74\" tried to access using \"86.161.75.144\" as host.","userAgent":"Mozilla\/5.0 (X11; Linux x86_64) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/34.0.1847.137 Safari\/537.36","version":"12.0.3.3"}
{"reqId":"WhKAZ38AAQEAAAUsF7IAAABC","level":2,"time":"2017-11-20T07:12:39+00:00","remoteAddr":"60.191.38.78","user":"--","app":"core","method":"GET","url":"\/","message":"Trusted domain error. \"60.191.38.78\" tried to access using \"86.161.75.144:443\" as host.","userAgent":"Mozilla\/5.0 (Macintosh; Intel Mac OS X 10.11; rv:47.0) Gecko\/20100101 Firefox\/47.0","version":"12.0.3.3"}
{"reqId":"WhKqi38AAQEAAAUr0bIAAAAE","level":3,"time":"2017-11-20T10:12:27+00:00","remoteAddr":"41.217.204.98","user":"--","app":"PHP","method":"GET","url":"\/admin\/config.php","message":"Exception: The requested uri(\/admin\/config.php) cannot be processed by the script '\/core\/templates\/404.php') at \/var\/www\/nextcloud\/lib\/private\/AppFramework\/Http\/Request.php#729","userAgent":"curl\/7.19.7 (x86_64-redhat-linux-gnu) libcurl\/7.19.7 NSS\/3.13.1.0 zlib\/1.2.3 libidn\/1.18 libssh2\/1.2.2","version":"12.0.3.3"}
{"reqId":"WhK1e38AAQEAAAUsF7QAAABD","level":2,"time":"2017-11-20T10:59:07+00:00","remoteAddr":"139.162.106.181","user":"--","app":"core","method":"GET","url":"\/","message":"Trusted domain error. \"139.162.106.181\" tried to access using \"86.161.75.144\" as host.","userAgent":"Mozilla\/5.0 (Windows NT 10.0; WOW64) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/50.0.2661.102 Safari\/537.36","version":"12.0.3.3"}
{"reqId":"WhLhgH8AAQEAAAUr0bQAAAAH","level":2,"time":"2017-11-20T14:06:56+00:00","remoteAddr":"184.105.247.195","user":"--","app":"core","method":"GET","url":"\/","message":"Trusted domain error. \"184.105.247.195\" tried to access using \"86.161.75.144\" as host.","userAgent":"--","version":"12.0.3.3"}
{"reqId":"WhMv7n8AAQEAAAUsGCUAAFYW","level":3,"time":"2017-11-20T19:41:34+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"GET","url":"\/index.php\/apps\/firstrunwizard\/wizard","message":"Cannot declare class , because the name is already in use at \/var\/www\/nextcloud\/apps\/firstrunwizard\/lib\/Controller\/WizardController.php#31","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhMv-X8AAQEAAAUr0owAABUQ","level":3,"time":"2017-11-20T19:41:49+00:00","remoteAddr":"86.161.75.144","user":"ash","app":"PHP","method":"DELETE","url":"\/index.php\/apps\/firstrunwizard\/wizard","message":"Cannot declare class , because the name is already in use at \/var\/www\/nextcloud\/apps\/firstrunwizard\/lib\/Controller\/WizardController.php#31","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhMwF38AAQEAAAUr0poAABcB","level":3,"time":"2017-11-20T19:42:16+00:00","remoteAddr":"86.161.75.144","user":"admin","app":"PHP","method":"GET","url":"\/index.php\/settings\/apps","message":"Class 'OC\\App\\AppStore\\Fetcher\\Fetcher' not found at \/var\/www\/nextcloud\/lib\/private\/App\/AppStore\/Fetcher\/CategoryFetcher.php#30","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhMwPH8AAQEAAAUr0rQAAAMG","level":3,"time":"2017-11-20T19:42:52+00:00","remoteAddr":"86.161.75.144","user":"admin","app":"PHP","method":"GET","url":"\/index.php\/settings\/personal","message":"Cannot redeclare {closure}() (previously declared in \/var\/www\/nextcloud\/settings\/personal.php:257) at \/var\/www\/nextcloud\/settings\/personal.php#232","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhMwrX8AAQEAAAUr0s0AAAgL","level":3,"time":"2017-11-20T19:44:46+00:00","remoteAddr":"86.161.75.144","user":"admin","app":"PHP","method":"GET","url":"\/index.php\/settings\/personal","message":"Cannot redeclare {closure}() (previously declared in \/var\/www\/nextcloud\/settings\/personal.php:257) at \/var\/www\/nextcloud\/settings\/personal.php#232","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}
{"reqId":"WhMwtH8AAQEAAAUr0s4AAAkJ","level":3,"time":"2017-11-20T19:44:52+00:00","remoteAddr":"86.161.75.144","user":"admin","app":"PHP","method":"GET","url":"\/index.php\/settings\/personal","message":"Allowed memory size of 805306368 bytes exhausted (tried to allocate 1198810504 bytes) at \/var\/www\/nextcloud\/lib\/private\/legacy\/util.php#525","userAgent":"Mozilla\/5.0 (X11; Linux i686) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/61.0.3163.102 Safari\/537.36 Vivaldi\/1.93.955.48","version":"12.0.3.3"}