Iserror works on one column but not two in small nested formula

Hello People..
I'm trying to get Iserror to ignore #N/A errors from a chart data area. I'm wanting to count the number of times in a row something happens, that bit I can do. I'm trying to get Iserror to ignore the errors in columns KE6:KE51 & KF6:KF51. I can only get it to ignore one column or the other, not both at the same time. I need to combine the occurrences of "1" in both columns & have them appear in column KB if they are in the other columns. If not leave the cell blank. I'm having to do this as counting a run of entries doesn't work with errors in the column. Hoping this explanation is clear enough
I've attached an example
Any ideas please.
Thanks

Hi Pepe.. I've tried various ways of doing it & can only get it to do 1/2 a job. I was trying to get it to ignore other numbers in the KE column. I could get it to do all the numbers, or get a partial result. Both no good for what I need. I've done it with a helper column & ISNUMBER
If you can think of a better way, I'm all ears
I've attached what I've done so you can see what I mean
Cheers
Phil

I want to count the latest run on columns KK KL &KM. At the moment that would be 1, as there's no 1's 2's or 3's grouped together. I can do that ok though. I was trying to get the 1's from columns KE & KF to run one after the other in another column (JX or JY), but gave up after trying everything I could think of. I did it with the helper column as I couldn't the other way.
Probably clear as mud
Cheers

Yep, pretty muddy. Probably my brain, though. I'm about to sign off for the night so I'll have another look at it in the morning.

Maybe you could upload a file showing the results you want and a clear explanation as to the logic in arriving at those results.

I set it out a bit better. KO, KP & KQ6 count the runs of 1's 2's & 3's from KK, KL, & KM6:51
The failed attempts are attempting to replicate the column of 1's in the countable data.
Hopefully a bit clearer

Thank you vlady, that's exactly what I've been trying to do. I can see how it works & it's nice & simple
Cheers
Phil