Add-ins are forward compatible, so an Add-in created at version 10.1 should successfully install at 10.2.x and 10.3. x with no error, and without the need to be re-compiled at the newer version. The converse is NOT true. An Add-in created at 10.3.x would not work on a machine that has ArcGIS 10.2.x or 10.1 installed on it; it would have to be re-compiled for these earlier versions.
For an Add-in to install successfully, the user logged in to the machine should have read/write permissions to the so-called "Well-Known folder":
- C:\Users\YourUserName\Documents\ArcGIS\AddIns\Desktop10.3
This is where the Add-in gets installed. It is possible that if the user does not have the appropriate permissions, the installation of the Add-in will fail.
For more information, please have a look at the documentation on Advanced Add-in concepts.
http://resources.arcgis.com/en/help/arcobjects-net/conceptualhelp/index.html#/Advanced_add_in_concep...