The table "" doesn't have a column "keywords"
But a column with keywords is needed for the xBlog pluigin tag cloud.
Maybe this TCA property must configured:
TCA..ctrl.xblog.pi18.tagfield = your column with keywords
See details in the manual.
Sorry for the trouble. Error occors @ Netzmacher\Xblog\Controller\TagcloudController::_getTagfield#151