PHP Fatal error: Class name must be a valid object or a string in drupal-7.15/includes/common.inc

the line is:
$controllers[$entity_type] = new $class($entity_type);

I enabled the following:
multivariate

I did not set anything up in settings or config
I disabled multivariate and the problem went away.

Is there an issue with multivariate_test?

Could it be related to this:
http://drupal.org/node/1667536#comment-6188394

Here is a snippet of the debug output:

[13] => Array ( [file] => /var/aegir/platforms/7/modules/all/entity/views/entity.views.inc [line] => 399 [function] => entity_get_property_info [args] => Array ( [0] => multivariate_test ) ) [14] => Array ( [file] => /var/aegir/platforms/7/modules/all/entity/views/entity.views.inc [line] => 385 [function] => schema_fields [class] => EntityDefaultViewsController [object] => EntityDefaultViewsController Object ( [type:protected] => multivariate_test [info:protected] => Array ( [label] => Multivariate Test [entity class] => MultivariateTest [controller class] => MultivariateTestController [base table] => multivariate_test [fieldable] => [exportable] => 1 [entity keys] => Array ( [id] => mtid [revision] => [bundle] => ) [load hook] => multivariate_test_load [view modes] => Array ( [full] => Array ( [label] => Default [custom settings] => ) ) [label callback] => entity_class_label [uri callback] => entity_class_uri [module] => multivariate [access callback] => multivariate_access [static cache] => 1 [field cache] => 1 [bundles] => Array ( [multivariate_test] => Array ( [label] => Multivariate Test ) ) [translation] => Array ( ) [schema_fields_sql] => Array ( [base table] => Array ( [0] => mtid [1] => title [2] => uid [3] => created [4] => changed [5] => description [6] => enabled [7] => run_condition [8] => variants_set [9] => success_condition [10] => status [11] => module ) ) ) [relationships:protected] => Array ( ) ) [type] => -> [args] => Array ( ) ) [15] => Array ( [file] => /var/aegir/platforms/7/modules/all/entity/views/entity.views.inc [line] => 33 [function] => views_data [class] => EntityDefaultViewsController [object] => EntityDefaultViewsController Object ( [type:protected] => multivariate_test [info:protected] => Array ( [label] => Multivariate Test [entity class] => MultivariateTest [controller class] => MultivariateTestController [base table] => multivariate_test [fieldable] => [exportable] => 1 [entity keys] => Array ( [id] => mtid [revision] => [bundle] => ) [load hook] => multivariate_test_load [view modes] => Array ( [full] => Array ( [label] => Default [custom settings] => ) ) [label callback] => entity_class_label [uri callback] => entity_class_uri [module] => multivariate [access callback] => multivariate_access [static cache] => 1 [field cache] => 1 [bundles] => Array ( [multivariate_test] => Array ( [label] => Multivariate Test ) ) [translation] => Array ( ) [schema_fields_sql] => Array ( [base table] => Array ( [0] => mtid [1] => title [2] => uid [3] => created [4] => changed [5] => description [6] => enabled [7] => run_condition [8] => variants_set [9] => success_condition [10] => status [11] => module ) ) )