How to avoid #spill error in formula?

[squeakums]

I have this new formula I'm using and it is causing a #spill error for just one cell. The others are fine.

=IFERROR(TOCOL(IF(SEARCH(Guide!$A$17:$A$26,AD136),Guide!$B$17:$B$26),2),"Other")

is it because the text in AD136 is too long? I shortened it and it pulls in something. But, that text will always be long. How do I avoid this error?

 

[Fluff]

The #spill error simply means that the formula is trying to return more than 1 value & there is something in the next cell that prevents it from spilling.