Piwik: Must call allocateNewArchiveId() first

I have been using Piwik 2.6.1 happily as usual this month. But today when I logged in, everything except “Visitors in Real-time” failed on my dashboard with the error message:

WARN VisitsSummary[2014-09-26 14:48:15] [9bf30] Failed to get data from API: Must call allocateNewArchiveId() first#0 /home/elftrnix/public_html/piwik/core/DataAccess/ArchiveWriter.php(289): Piwik\DataAccess\ArchiveWriter->getIdArchive()#1 /home/elftrnix/public_html/piwik/core/DataAccess/ArchiveWriter.php(280): Piwik\DataAccess\ArchiveWriter->getInsertRecordBind()#2 /home/elftrnix/public_html/piwik/core/DataAccess/ArchiveWriter.php(201): Piwik\DataAccess\ArchiveWriter->insertRecord(‘done’, 2)#3 /home/elftrnix/public_html/piwik/core/DataAccess/ArchiveWriter.php(117): Piwik\DataAccess\ArchiveWriter->logArchiveStatusAsIncomplete()#4 /home/elftrnix/public_html/piwik/core/ArchiveProcessor/PluginsArchiver.php(45): Piwik\DataAccess\ArchiveWriter->initNewArchive()#5 /home/elftrnix/public_html/piwik/core/ArchiveProcessor/Loader.php(110): Piwik\ArchiveProcessor\PluginsArchiver->__construct(Object(Piwik\ArchiveProcessor\Parameters), true)#6 /home/elftrnix/public_html/piwik/core/ArchiveProcessor/Loader.php(73): Piwik\ArchiveProcessor\Loader->prepareAllPluginsArchive(false, false)#7 /home/elftrnix/public_html/piwik/core/Archive.php(801): Piwik\ArchiveProcessor\Loader->prepareArchive(‘VisitsSummary’)#8 /home/elftrnix/public_html/piwik/core/Archive.php(614): Piwik\Archive->prepareArchive(Array, Object(Piwik\Site), Object(Piwik\Period\Month))#9 /home/elftrnix/public_html/piwik/core/Archive.php(556): Piwik\Archive->cacheArchiveIdsAfterLaunching(Array, Array)#10 /home/elftrnix/public_html/piwik/core/Archive.php(497): Piwik\Archive->getArchiveIds(Array)#11 /home/elftrnix/public_html/piwik/core/Archive.php(341): Piwik\Archive->get(Array, ‘numeric’)#12 /home/elftrnix/public_html/piwik/plugins/VisitsSummary/API.php(59): Piwik\Archive->getDataTableFromNumeric(Array)#13 [internal function]: Piwik\Plugins\VisitsSummary\API->get(‘1’, ‘month’, ‘2012-10-01,2014…’, false, ‘nb_visits’)#14 /home/elftrnix/public_html/piwik/core/API/Proxy.php(209): call_user_func_array(Array, Array)#15 /home/elftrnix/public_html/piwik/plugins/API/API.php(403): Piwik\API\Proxy->call(‘\Piwik\Plugins.…’, ‘get’, Array)#16 [internal function]: Piwik\Plugins\API\API->get(‘1’, ‘month’, ‘2012-10-01,2014…’, false, ‘nb_visits’)#17 /home/elftrnix/public_html/piwik/core/API/Proxy.php(209): call_user_func_array(Array, Array)#18 /home/elftrnix/public_html/piwik/core/API/Request.php(216): Piwik\API\Proxy->call(‘\Piwik\Plugins.…’, ‘get’, Array)#19 /home/elftrnix/public_html/piwik/core/ViewDataTable/Request.php(48): Piwik\API\Request->process()#20 /home/elftrnix/public_html/piwik/core/Plugin/ViewDataTable.php(327): Piwik\ViewDataTable\Request->loadDataTableFromAPI(Array)#21 /home/elftrnix/public_html/piwik/core/Plugin/Visualization.php(166): Piwik\Plugin\ViewDataTable->loadDataTableFromAPI(Array)#22 /home/elftrnix/public_html/piwik/core/Plugin/ViewDataTable.php(414): Piwik\Plugin\Visualization->buildView()#23 /home/elftrnix/public_html/piwik/core/Plugin/Controller.php(248): Piwik\Plugin\ViewDataTable->render()#24 /home/elftrnix/public_html/piwik/plugins/VisitsSummary/Controller.php(104): Piwik\Plugin\Controller->renderView(Object(Piwik\Plugins\CoreVisualizations\Visualizations\JqplotGraph\Evolution))#25 [internal function]: Piwik\Plugins\VisitsSummary\Controller->getEvolutionGraph()#26 /home/elftrnix/public_html/piwik/core/FrontController.php(577): call_user_func_array(Array, Array)#27 /home/elftrnix/public_html/piwik/core/FrontController.php(86): Piwik\FrontController->doDispatch(NULL, NULL, NULL)#28 /home/elftrnix/public_html/piwik/core/dispatch.php(34): Piwik\FrontController->dispatch()#29 /home/elftrnix/public_html/piwik/index.php(46): require_once(‘/home/elftrnix/…’)#30 {main}
Must call allocateNewArchiveId() first

I saw http://forum.piwik.org/read.php?2,109651

and tried to delete the tables: piwik_archive_numeric_2014_09 & piwik_archive_blob_2014_09 with no result.

also I tried to update to Piwik 2.7.0.

Please help! Thanks in advance!

Well, I have no idea what happened. But the next day it is working again. Perhaps deleting the tables helped. Who knows.