Error converting a script from Leopard to Mountain Lion

Here is a part of the old code that gets hung up. It gives the error “Data is being accessed by another user, script, or transaction” when it gets to “set adState” to cell “list State” of current record."

tell application “FileMaker Pro”
tell document “2015 Database”
go to layout “Spec Ads”
do script “Find all records”
show (every record whose cell “Spec Ad Number” = docName)
set adState to cell “List State” of current record
if adState = “” then
activate
beep 2
display dialog “There is no Ad State for this record.” buttons {“OK”} default button 1 with icon 1 giving up after 10
return 0
end if
Finder_HF(docName) of me
if isThere = false then
activate
display dialog "There is no PDF file for the Quark layout " & docName & return & return & “Please check the Acrobat Distiller application for errors.” buttons {“OK”} default button 1 with icon 0 giving up after 5
return 0
end if
end tell
end tell

Thanks
Rob