Provide reason for unable to merge (mobile)
Error from the mobile app (Android). When attempting to merge two individuals, there is no reason provided. Please provide a specific reason for why the two cannot be merged. Inform the user of any steps they can take to improve the likelihood of allowing the merge.
In addition -- please review the various reasons as to why the two cannot be merged. For instance, it often helps to just switch the two individuals and try the merge again. So, if its a matter that individuals must be merged in a certain order, then load the merge in that order instead of declaring that they cannot be merged. In other cases, waiting a few minutes makes a difference. Again, not an instance where the two cannot be merged -- but something hadn't quite saved back to the main site. In other cases I've seen, the app was not able to save, but the desktop version had no issues. Please validate each instance and resolve as much as possible behind the scenes. Its very frustrating for the app to indicate that two individuals "cannot" be merged, when the desktop version has no issues.
As an aside ...
IF, you have not already; THEN, can I humbly suggest that you also post this 'Feedback' on/through the 'Feedback' in the "Mobile" Application of "Family Tree" of 'FamilySearch' itself, as well.
Such 'Feedback' would certainly get to the Team developing and designing the "Mobile" Application, a lot quicker.
Just a thought.