TYPO3 Core

Using TYPO3 7.6.15 and its workspace extension with MySQL 5.7 is broken.

When switching to a non-live workspace the page tree does not get printed anymore, and the exception panel pops up:

exec_SELECTquery
array(4 items)
   caller => 'TYPO3\CMS\Core\Database\DatabaseConnection::exec_SELECTquery' (60 chars)
   ERROR => 'Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggre
      gated column 'TYPO3.B.uid' which is not functionally dependent on columns in
       GROUP BY clause; this is incompatible with sql_mode=only_full_group_by' (223 chars)
   lastBuiltQuery => 'SELECT B.uid as live_uid, B.pid as live_pid, A.uid as offline_uid FROM sys_c
      ategory A,sys_category B WHERE A.pid=-1 AND A.t3ver_wsid=1 AND (A.t3ver_oid=
      B.uid AND A.t3ver_state<>4 OR A.t3ver_oid=B.t3ver_move_id AND A.t3ver_
      state=4) AND A.deleted=0 AND B.deleted=0 GROUP BY live_pid' (280 chars)
   debug_backtrace => '{closure}#21 // TYPO3\CMS\Backend\Http\Application->run#20 // TYPO3\CMS\C
      ore\Core\Bootstrap->handleRequest#94 // TYPO3\CMS\Backend\Http\AjaxReques
      tHandler->handleRequest#302 // TYPO3\CMS\Backend\Http\AjaxRequestHandler-
      >dispatch#88 // TYPO3\CMS\Backend\Http\RouteDispatcher->dispatch#170 /
      / call_user_func_array#54 // TYPO3\CMS\Core\ExtDirect\ExtDirectRouter->ro
      uteAction# // TYPO3\CMS\Core\ExtDirect\ExtDirectRouter->processRpc#87 // 
      call_user_func_array#139 // TYPO3\CMS\Backend\Tree\Pagetree\ExtdirectTreeDat
      aProvider->getNextTreeLevel# // TYPO3\CMS\Backend\Tree\Pagetree\DataProvi
      der->getTreeMounts#84 // TYPO3\CMS\Backend\Tree\Pagetree\DataProvider->
      ;getNodes#405 // TYPO3\CMS\Backend\Tree\Pagetree\DataProvider->getNodes#1
      69 // TYPO3\CMS\Backend\Tree\Pagetree\DataProvider->getNodes#169 // TYPO3
      \CMS\Backend\Tree\Pagetree\DataProvider->getNodes#169 // TYPO3\CMS\Worksp
      aces\ExtDirect\PagetreeCollectionsProcessor->postProcessGetNodes#183 // T
      YPO3\CMS\Workspaces\ExtDirect\PagetreeCollectionsProcessor->highlightVers
      ionizedElements#42 // TYPO3\CMS\Workspaces\Service\WorkspaceService->hasP
      ageRecordVersions#85 // TYPO3\CMS\Core\Database\DatabaseConnection->exec_
      SELECTgetRows#757 // TYPO3\CMS\Core\Database\DatabaseConnection->exec_SEL
      ECTquery#377 // TYPO3\CMS\Core\Database\DatabaseConnection->debug#314' (1307 chars)