I recently downloaded the trial version of FinalBuilder 6 (6.3.0.1712 specifically). I noticed that when a variable name is contained within parenthesis, the popup seems to parse it wrong. You can see this by creating a new project with 2 project variables - say TEST1 & TEST2. Set their default values to something (e.g. Test1 & Test2). Then add an action "Set Variable". In this action, choose:
Set Variable: TEST2
New value:
o New value:
(%TEST1%)
You'll then see the popup message "No Variables match : %)"
Note that the action itself works fine. It's just the popup that seems to parse improperly. Also, I presume this issue occurs in all dialogs as I originally saw this problem in another Dialog - Send Email (SMTP) - where I was trying to set the "Subject" line. Adding a space between the "%" and the ")" is a workaround.