Media Browser thrown exception

I have a system with two users, when opening the media browser I get following exceptions:

Exception #1222268609 in line 62 of …/Data/Temporary/Production/Cache/Code/Flow_Object_Classes/TYPO3_Flow_Security_Aspect_PolicyEnforcementAspect.php: Access denied for method
Method: TYPO3\TYPO3CR\Domain\Service\Context::validateWorkspace()

Evaluated following 1 privilege target(s):
"TYPO3.Neos:Backend.OtherUsersPersonalWorkspaceAccess": ABSTAIN
(0 granted, 0 denied, 1 abstained)

Authenticated roles: TYPO3.Flow:Everybody, TYPO3.Flow:AuthenticatedUser, TYPO3.Neos:LivePublisher, TYPO3.Neos:RestrictedEditor, TYPO3.Neos:AbstractEditor, TYPO3.TYPO3CR:Administrator, TYPO3.Neos:Editor

19 TYPO3\Flow\Security\Authorization\Interceptor\PolicyEnforcement_Original::invoke()
18 TYPO3\Flow\Security\Aspect\PolicyEnforcementAspect_Original::enforcePolicy(TYPO3\Flow\Aop\JoinPoint)
17 TYPO3\Flow\Aop\Advice\AroundAdvice::invoke(TYPO3\Flow\Aop\JoinPoint)
16 TYPO3\Flow\Aop\Advice\AdviceChain::proceed(TYPO3\Flow\Aop\JoinPoint)
15 TYPO3\TYPO3CR\Domain\Service\Context::validateWorkspace(TYPO3\TYPO3CR\Domain\Model\Workspace)
14 TYPO3\TYPO3CR\Domain\Service\Context_Original::getWorkspace(FALSE)
13 TYPO3\TYPO3CR\TypeConverter\NodeConverter_Original::convertFrom(array|1|, "TYPO3\TYPO3CR\Domain\Model\NodeInterface", array|0|, TYPO3\Flow\Mvc\Controller\MvcPropertyMappingConfiguration)
12 TYPO3\Flow\Property\PropertyMapper_Original::doMapping("/sites/foundation-site/node-57b9bcb3a38b0/node-57aa363fdfafb@user-rolandschuetz;language=en", "TYPO3\TYPO3CR\Domain\Model\NodeInterface", TYPO3\Flow\Mvc\Controller\MvcPropertyMappingConfiguration, array|0|)
11 TYPO3\Flow\Property\PropertyMapper_Original::convert("/sites/foundation-site/node-57b9bcb3a38b0/node-57aa363fdfafb@user-rolandschuetz;language=en", "TYPO3\TYPO3CR\Domain\Model\NodeInterface", TYPO3\Flow\Mvc\Controller\MvcPropertyMappingConfiguration)
10 TYPO3\Flow\Mvc\Controller\Argument_Original::setValue("/sites/foundation-site/node-57b9bcb3a38b0/node-57aa363fdfafb@user-rolandschuetz;language=en")
9 TYPO3\Flow\Mvc\Controller\AbstractController_Original::mapRequestArgumentsToControllerArguments()
8 TYPO3\Flow\Mvc\Controller\ActionController_Original::processRequest(TYPO3\Flow\Mvc\ActionRequest, TYPO3\Flow\Http\Response)
7 TYPO3\Flow\Mvc\Dispatcher_Original::initiateDispatchLoop(TYPO3\Flow\Mvc\ActionRequest, TYPO3\Flow\Http\Response)
6 TYPO3\Flow\Mvc\Dispatcher_Original::dispatch(TYPO3\Flow\Mvc\ActionRequest, TYPO3\Flow\Http\Response)
5 TYPO3\Flow\Mvc\DispatchComponent_Original::handle(TYPO3\Flow\Http\Component\ComponentContext)
4 TYPO3\Flow\Http\Component\ComponentChain_Original::handle(TYPO3\Flow\Http\Component\ComponentContext)
3 TYPO3\Flow\Http\Component\ComponentChain_Original::handle(TYPO3\Flow\Http\Component\ComponentContext)
2 TYPO3\Flow\Http\RequestHandler::handleRequest()
1 TYPO3\Flow\Core\Bootstrap::run()

HTTP REQUEST:
GET /en/models/basis@user-rolandschuetz;language=en.html HTTP/1.1
Accept-Language: de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4
Accept-Encoding: gzip, deflate, sdch
Dnt: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36
X-Requested-With: XMLHttpRequest
Accept: */*
Connection: close
X-Forwarded-Port: 80
X-Forwarded-For: 80.110.10.145
X-Real-Ip: 80.110.10.145
Host: carado.de



HTTP RESPONSE:
[response was empty]

PHP PROCESS:
Inode: 4201491
PID: 757
UID: 1447
GID: 1447
User: neos`

What could that be?

Which Neos-Version are you using exactly?

I also have some problems with the image browswer. please see:

There are definitely some bugs to fix, I think.