I had this problem after another upgrade and can't figure out how I solved it! (Posted as an issue at github as well.)
Extension installed, Enabled | ver 1.2 and at /home/MYSITEDIR/public_html/sites/all/civiextensions/me.twomice.civicrm.aggregatehouseholdcontributions
All existing reports error out with:
Fatal error: require_once(): Failed opening required 'CRM/Aggregatehouseholdcontributions/Report/Form/Contribute/AggregatedHouseholds.php' (include_path='/home/MYSITEDIR/public_html/sites/all/civiextensions/com.iatspayments.civicrm/:/home/MYSITEDIR/public_html/sites/all/civiextensions/de.systopia.householdmerge-1.1.beta/:/home/MYSITEDIR/public_html/sites/all/civiextensions/com.pogstone.fancytokens/:/home/MYSITEDIR/public_html/sites/all/civiextensions/nz.co.fuzion.cssinline/:.:/home/MYSITEDIR/public_html/sites/all/modules/civicrm:/home/MYSITEDIR/public_html/sites/all/modules/civicrm/packages:.:/home/MYSITEDIR/public_html/sites/all/modules/civicrm:/home/MYSITEDIR/public_html/sites/all/modules/civicrm/packages:/home/MYSITEDIR/public_html/sites/all/modules/civicrm/vendor/tecnickcom:/home/MYSITEDIR/public_html/sites/all/modules/civicrm/vendor/phpseclib/phpseclib/phpseclib:/home/MYSITEDIR/public_html/sites/all/modules/civicrm/vendor/pear/pear_exception:/home/MYSITEDIR/public_html/ in /home/MYSITEDIR/public_html/sites/all/modules/civicrm/CRM/Core/Controller.php on line 451
A file by that name is at: /home/MYSITEDIR/public_html/sites/default/files/civicrm/custom/customphp/CRM/Report/Form/Contribute/AggregatedHouseholds.php
Copying it to: /home/MYSITEDIR/public_html/sites/default/files/civicrm/custom/customphp/CRM/Aggregatehouseholdcontributions/Report/Form/Contribute/AggregatedHouseholds.php does NOT fix it.
The code referenced is require_once str_replace('', DIRECTORY_SEPARATOR, $className) . '.php'; in the snippet below
$ext = CRM_Extension_System::singleton()->getMapper(); if ($ext->isExtensionClass($className)) { require_once $ext->classToPath($className); } else { require_once str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php'; }