Hello @Anonymous
Can you share a picture of your flow,
Which entity are you so tiring the users in?
If you are using the entity Users, the user needs to be apart of the entity Users.
Also to note. Where you are assigning the user to the record, if the assigned to field is a lookup. Than you need to pass the GUID (ID) of the user.
This can be done by using a list records on the Users entity, filtering on email address to get the UserID
—Josh
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