error when trying to clear the cache in drupal I was going to use mailchimp module to create my newsletter but an error revealed saying that i should  install the version 2.0 of librairies, so i delete both modules, started again,that worked just fine .
When i went to  settings of mailchimp, this error revealed:


  1)Fatal error: Call to undefined function
  mailchimp_signup_entity_access() in
  C:\Users\user\Sites\devdesktop\drupal-7.37\sites\all\modules\entity\entity.module
  on line 657



So , i tried to clear caches ,another error revealed:


  2)
   i-Warning: Invalid argument supplied for foreach() in
  drupal_schema_field_types() (line 7159 of
  C:\Users\user\Sites\devdesktop\drupal-7.37\includes\common.inc).
  ii-Notice: Undefined variable: field_types in
  drupal_schema_field_types() (line 7162 of
  C:\Users\user\Sites\devdesktop\drupal-7.37\includes\common.inc).
  iii-Warning: array_keys() expects parameter 1 to be array, null given
  in drupal_schema_fields_sql() (line 7179 of
  C:\Users\user\Sites\devdesktop\drupal-7.37\includes\common.inc).
  and Recoverable fatal error: Argument 2 passed to
  SelectQuery::fields() must be of the type array, null given, called in
  C:\Users\user\Sites\devdesktop\drupal-7.37\includes\entity.inc on line
  317 and defined in SelectQuery->fields() (line 1301 of
  C:\Users\user\Sites\devdesktop\drupal-7.37\includes\database\select.inc).


 any help please!
If the on option is grey, it means the module is required by another one. Deleting it will cause other modules to break. The correct thing to do would be to disable the depending modules, then disable the main modules and then go to the 'uninstall' tab and uninstall the module. 

But for now try running update.php (drush updb) first and see if it helps. If not. Uninstall the modules properly, install the previous versions, disable and uninstall the previous versions and then install new versions again.

This works in most cases.