Index 50 out of bounds for length 50

I’m using a ‘Record’ type variable and I’m getting it’s contents through named columns, as shown in the attachment.

All the other columns work fine, except this one. I get the following error when it tries to run this code:

‘Index 50 out of bounds for length 50’

Coincidentally it is the last column of the row, but I’m not using a numbered index, I’m using a named index

How do I solve this?