Setting a Lookup Column via an Action (Button)

[Asaf_Dafna]

Two general “tips” (not directly related to your question):

1. It’s recommended to use Filter() instead of Lookup(), in your case [Table 1].Filter([add this row]=true).First() instead of [Table1].Lookup([Add this row], true).First().
   See this thread (answers in post #6 & #7): Filter() vs Lookup() — what’s the difference really?

2. Since your filter is based on a checkbox column, you can use [Table 1].Filter([add this row]).First() since the value of the [add this row] column is already true or false.