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Let's now interpret the error. Mainly, Case Sharing is enabled and CommCare is responsible for determining the owner of cases but because of some incorrect user configuration or many options available, . However, the user is either configured incorrectly or they are associated with too many locations or case sharing groups, so CommCare gets "confused" and throws that error, so potentiallythis error. Often, this could can be solved by setting the ownership manually. An important note here is that, in most of the scenarios this error is directly related with to some design decision made for the app, so before implementing a solution, it's good practice to revisit documentation to ensure that whatever whichever solution is applied it won't break any workflow. Let's see the potential situations

The following is a list of example scenarios that could lead to this error coming up:

1. User is not assigned to a Location or Case sharing group - without a Location or Case Sharing Group associated to the mobile user, CommCare is forced to set the ownership to the user but . However, setting the ownership to the user will automatically prevent the case from being shared, so CommCare prevents this behavior from happening automatically.
   1. Solution: assign the user to a Location or a Case Sharing Group
2. User is assigned to more than one case sharing group and/or location - considering that there are many options available, CommCare is unable to decide on who should be the rightful owner therefore , resulting in that same error being thrown. This also applies if the user is assigned to one Case Sharing Group and one Location when the Organizational Level is set to Own Cases (see more in Setting up Organization Levels and Structure).
   1. Solution: There are two potential approaches here, . You can change the configuration of the user in terms of to how many Case Sharing Groups so that they are only assigned to a single Case Sharing Group (see more in Mobile Worker Groups) or Locations Location (see more in Assigning Mobile Workers to a Location) they are assigned to or . Alternatively, you set the ownership manually within the form (see below).
3. User is assigned to a Location that can't Own cases - in this scenario, CommCare sees that the user is assigned to a Location that, according to the configuration of the Organization Level, can't own Cases.

   1. Solution: There are two potential approaches here, . You can change the configuration of the location to allow it to own cases (see more in Setting up Organization Levels and Structure), or you can set the ownership manually (see below).

4. User is assigned to a Location with child Locations and View Child Data is Enabled - this is a more complex problem to solve because apparently . In this case, it typically appears that the users are correctly configured, and that each one is assigned to a single location. But, what happens in reality is that CommCare actually creates a Case Sharing Group to link the parent location to each one of its children resulting in several groups being created, depending on the number of children. So, a user placed in this parent location is under several Case Sharing Groups plus in their own location and if they try to create a case CommCare doesn't know how to set its ownership. Visually, it would be something similar to:However, since the user has access to data in the child locations as well, the child locations are also considered valid candidates for case sharing, similarly to if the user was actually assigned to multiple locations as outlined above.
   In this example, we can conclude that Nurse should be able to see cases from their CHWs and also to have their own cases. The error would occur when Nurse tries to create a new case, however, the app should work fine for CHW 1 and 2.
   
   1. Solution: In this case, usually the only viable option is to set the ownership manually. Of course, you could set turn the View Child Data option off but this would most likely go against the workflow of the app.   

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1.  (REMOVE THIS BEFORE PUBLISHING) This originally read: But, what happens in reality is that CommCare actually creates a Case Sharing Group to link the parent location to each one of its children resulting in several groups being created, depending on the number of children. So, a user placed in this parent location is under several Case Sharing Groups plus in their own location and if they try to create a case CommCare doesn't know how to set its ownership. Visually, it would be something similar to:

Setting the Ownership of a

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Case Manually

So, at this point it's safe to assume that you have exhausted all other options and decided to set the ownership of the case manually. First we need the ID of the owner, this can be achieved either by having the user selecting a Location or a Case Sharing group from a Multiple Choice Lookup Table question or some calculation that returns a single ID. Next, we need to instruct CommCare to assign the ownership based on that ID, for that we need to set in the Case Management, of the form creating the case, a special property called owner_id, this is the property that holds the ID of the owner of the case. In the end you should have something like:

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