This error started appearing after applying the patch https://www.drupal.org/commitlog/commit/65985/2106e1024fd0d498b9afc44210...
Which solved the issue nr 2810549.

An error appears when an activity is saved that contains a newsly created sales process. Error message:

EntityMetadataWrapperException: Invalid data value given. Be sure it matches the required data type and format. Value at crm_core_activity(): . in EntityDrupalWrapper->set() (line 756 of /home/erpal/public_html/profiles/erpal_platform/modules/contrib/entity/includes/entity.wrapper.inc).

To reproduce:
Create an activity, fill in required fields, use the 'create sales process link in the actifity form to create and save a sales process.
The sales process is saved without error and visible in its field in the activity form.
Save the activity.
Error appears mentioned above.

Comments

Yuri created an issue.