Making the request with following parameteres:

Url: /api/ezp/v2/user/roles/12
Method: "PATCH"
Body: "{"RoleInput":{"identifier":"random-role-id-0.5097913898323964"}}"

I'm receiving following Error Message:

{"_media-type":"application/vnd.ez.api.ErrorMessage+json","errorCode":500,"errorMessage":"Internal Server Error","errorDescription":"Notice: Trying to get property of non-object in E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\Persistence\\Cache
UserHandler.php line 174","trace":"#0 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\Persistence\\Cache
UserHandler.php(174): Symfony\\Component\\HttpKernel\\Debug
ErrorHandler->handle(8, 'Trying to get p...', 'E:\\_EZ\\GitHub
e...', 174, Array)\n#1 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\Repository
RoleService.php(203): eZ\\Publish\\Core\\Persistence\\Cache\\UserHandler->updateRole(Object(eZ\\Publish\\SPI\\Persistence\\User\\RoleUpdateStruct))\n#2 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\SignalSlot
RoleService.php(104): eZ\\Publish\\Core\\Repository\\RoleService->updateRole(Object(eZ\\Publish\\Core\\Repository\\Values\\User
Role), Object(eZ\\Publish\\API\\Repository\\Values\\User\\RoleUpdateStruct))\n#3 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\REST\\Server\\Controller
Role.php(150): eZ\\Publish\\Core\\SignalSlot\\RoleService->updateRole(Object(eZ\\Publish\\Core\\Repository\\Values\\User
Role), Object(eZ\\Publish\\API\\Repository\\Values\\User\\RoleUpdateStruct))\n#4 [internal function]: eZ\\Publish\\Core\\REST\\Server\\Controller\\Role->updateRole()\n#5 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\symfony\\symfony\\src\\Symfony\\Component\\HttpKernel
HttpKernel.php(129): call_user_func_array(Array, Array)\n#6 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\symfony\\symfony\\src\\Symfony\\Component\\HttpKernel
HttpKernel.php(73): Symfony\\Component\\HttpKernel\\HttpKernel->handleRaw(Object(Symfony\\Component\\HttpFoundation
Request), 1)\n#7 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\symfony\\symfony\\src\\Symfony\\Component\\HttpKernel\\DependencyInjection
ContainerAwareHttpKernel.php(57): Symfony\\Component\\HttpKernel\\HttpKernel->handle(Object(Symfony\\Component\\HttpFoundation
Request), 1, true)\n#8 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\symfony\\symfony\\src\\Symfony\\Component\\HttpKernel
Kernel.php(197): Symfony\\Component\\HttpKernel\\DependencyInjection\\ContainerAwareHttpKernel->handle(Object(Symfony\\Component\\HttpFoundation
Request), 1, true)\n#9 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\web
index.php(59): Symfony\\Component\\HttpKernel\\Kernel->handle(Object(Symfony\\Component\\HttpFoundation\\Request))\n#10 E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\web
index_dev.php(3): require('E:\\_EZ\\GitHub\\e...')\n#11

","file":"E:\\_EZ\\GitHub\\ezpublish-new\\ezpublish-community\\vendor\\ezsystems\\ezpublish-kernel\\eZ\\Publish\\Core\\Persistence\\Cache
UserHandler.php","line":174}

The same request was working on the version of REST interface checked out somewhere lately after the beginning of 2013.