Iam not getting collabora working properly after trying several different manuals 
iam using Debian Stretch with php7 and nginx to do so and changed already the storage engine of docker to devicemapper to avoid other problems.
I only get in nextlcoud an error about an internal error, but thats all (no further details). also the nginx log is empty, but the nextcloud log shows the following:
{“reqId”:“O8bruJpTW22nULffLHHS”,“level”:3,“time”:“2017-06-22T09:10:01+00:00”,“remoteAddr”:“62.218.23.122”,“user”:“devsibwarra”,“app”:“richdocuments”,“method”:“GET”,“url”:“/index.php/apps/richdocuments/index?fileId=268609&requesttoke$
{"Exception":"GuzzleHttp\\Exception\\ClientException","Message":"Client error response [url] https:\/\/office.collaboraserver\/hosting\/discovery [status code] 404 [reason phrase] Not
Found","Code":404,"Trace":"#0 \/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Subscriber\/HttpError.php(32):
GuzzleHttp\\Exception\\RequestException::create(Object(GuzzleHttp\\Message\\Request), Object(GuzzleHttp\\Message\\Response))\n#1
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Event\/Emitter.php(108): GuzzleHttp\\Subscriber\\HttpError->onComplete(Object(GuzzleHttp\\Event\\CompleteEvent), ‘complete’)\n#2
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/RequestFsm.php(91): GuzzleHttp\\Event\\Emitter->emit(‘complete’, Object(GuzzleHttp\\Event\\CompleteEvent))\n#3
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/RequestFsm.php(132): GuzzleHttp\\RequestFsm->__invoke(Object(GuzzleHttp\\Transaction))\n#4
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/react\/promise\/src\/FulfilledPromise.php(25): GuzzleHttp\\RequestFsm->GuzzleHttp\\{closure}(Array)\n#5
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/ringphp\/src\/Future\/CompletedFutureValue.php(55): React\\Promise\\FulfilledPromise->then(Object(Closure), NULL, NULL)\n#6
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Message\/FutureResponse.php(43): GuzzleHttp\\Ring\\Future\\CompletedFutureValue->then(Object(Closure), NULL, NULL)\n#7
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/RequestFsm.php(134): GuzzleHttp\\Message\\FutureResponse::proxy(Object(GuzzleHttp\\Ring\\Future\\CompletedFutureArray),
Object(Closure))\n#8 \/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/RequestFsm.php(132): GuzzleHttp\\RequestFsm->__invoke(Object(GuzzleHttp\\Transaction))\n#9
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/react\/promise\/src\/FulfilledPromise.php(25): GuzzleHttp\\RequestFsm->GuzzleHttp\\{closure}(Array)\n#10
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/ringphp\/src\/Future\/CompletedFutureValue.php(55): React\\Promise\\FulfilledPromise->then(Object(Closure), NULL, NULL)\n#11
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Message\/FutureResponse.php(43): GuzzleHttp\\Ring\\Future\\CompletedFutureValue->then(Object(Closure), NULL, NULL)\n#12
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/RequestFsm.php(134): GuzzleHttp\\Message\\FutureResponse::proxy(Object(GuzzleHttp\\Ring\\Future\\CompletedFutureArray),
Object(Closure))\n#13 \/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Client.php(165): GuzzleHttp\\RequestFsm->__invoke(Object(GuzzleHttp\\Transaction))\n#14
\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Client.php(125): GuzzleHttp\\Client->send(Object(GuzzleHttp\\Message\\Request))\n#15
\/var\/www\/collaboraserver\/nextcloud\/lib\/private\/Http\/Client\/Client.php(138): GuzzleHttp\\Client->get(‘office.collaborase…’, Array)\n#16
\/var\/www\/collaboraserver\/nextcloud\/apps\/richdocuments\/lib\/WOPI\/DiscoveryManager.php(84): OC\\Http\\Client\\Client->get(‘office.collaborase…’)\n#17
\/var\/www\/collaboraserver\/nextcloud\/apps\/richdocuments\/lib\/WOPI\/Parser.php(41): OCA\\Richdocuments\\WOPI\\DiscoveryManager->get()\n#18
\/var\/www\/collaboraserver\/nextcloud\/apps\/richdocuments\/lib\/TokenManager.php(117): OCA\\Richdocuments\\WOPI\\Parser->getUrlSrc(‘application\/vnd…’)\n#19
\/var\/www\/collaboraserver\/nextcloud\/apps\/richdocuments\/lib\/Controller\/DocumentController.php(108): OCA\\Richdocuments\\TokenManager->getToken(*** sensitive parameters replaced ***)\n#20 [internal
function]: OCA\\Richdocuments\\Controller\\DocumentController->index(‘268609’)\n#21 \/var\/www\/collaboraserver\/nextcloud\/lib\/private\/AppFramework\/Http\/Dispatcher.php(160): call_user_func_array(Array,
Array)\n#22 \/var\/www\/collaboraserver\/nextcloud\/lib\/private\/AppFramework\/Http\/Dispatcher.php(90):
OC\\AppFramework\\Http\\Dispatcher->executeController(Object(OCA\\Richdocuments\\Controller\\DocumentController), ‘index’)\n#23
\/var\/www\/collaboraserver\/nextcloud\/lib\/private\/AppFramework\/App.php(114): OC\\AppFramework\\Http\\Dispatcher->dispatch(Object(OCA\\Richdocuments\\Controller\\DocumentController), ‘index’)\n#24
\/var\/www\/collaboraserver\/nextcloud\/lib\/private\/AppFramework\/Routing\/RouteActionHandler.php(47): OC\\AppFramework\\App::main(‘OCA\\\\Richdocumen…’, ‘index’,
Object(OC\\AppFramework\\DependencyInjection\\DIContainer), Array)\n#25 [internal function]: OC\\AppFramework\\Routing\\RouteActionHandler->__invoke(Array)\n#26
\/var\/www\/collaboraserver\/nextcloud\/lib\/private\/Route\/Router.php(299): call_user_func(Object(OC\\AppFramework\\Routing\\RouteActionHandler), Array)\n#27
\/var\/www\/collaboraserver\/nextcloud\/lib\/base.php(1000): OC\\Route\\Router->match(‘\/apps\/richdocum…’)\n#28 \/var\/www\/collaboraserver\/nextcloud\/index.php(40): OC::handleRequest()\n#29
{main}","File":"\/var\/www\/collaboraserver\/nextcloud\/3rdparty\/guzzlehttp\/guzzle\/src\/Exception\/RequestException.php","Line":89}”,“userAgent”:“Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:54.0)
Gecko/20100101 Firefox/54.0”,“version”:“12.0.0.29”}
Somebody knows what the problem is? the collabora server and the nextcloud server are the same machine, and i used “–net host” to alow local connections, but after several tries i still have the problem that it isnt working 
Visiting /hosting/discovery delivers me an xml file but thats all.
Somebody knows what the error is or how i can analize the origin of the error properly?
Thanks!
Blubbsy