Excel =COPILOT() Errors: Fixing #NAME?, #BLOCKED!, #VALUE!, and #BUSY! (Admin Guide)
=COPILOT() errors fall into five classes: function recognition (#NAME?), content blocking (#BLOCKED!), input limits (#VALUE!), rate limiting (#BUSY!), and the silent failure where there is no error but the answer is wrong (hallucinations). The first four have clear fixes. The fifth is the dangerous one — it requires you to actually verify the output.