Erro: Unable to cast object of type "System.Double" to System.string

I need to read a specific line on my table:

1º) then I included the activity “Read Line”, to read the specific line, and now I need to go in each of the columns of this line, until I find an empty cell.

  1. Then, it included the “assign” activity to go through these columns. I used this formula:


I tried to convert but I didn’t succeed

and when the bot executes this error


This is my flow:

can someone help me with this problem?

Hi @lourena.coutinho,
Which step cause the problem?