Sagacity

F_S, I too use FF.au3 and MozRepl... Just a guess here, but if you have MozRepl installed in your Firefox browser, it has its own start, stop and "Activate at startup" found in the tools menu of Firefox. If MozRepl isn't running, the commands won't be executed since there is no connection. I see where you state that MozRepl is running...You can still use the following code if you would like. This will force Firefox to open. If you have MozRepl set to "Activate at startup", then you can debug from there. If FileExists(@ProgramFilesDir & "/Mozilla Firefox/firefox.exe") Then MsgBox($MB_ICONINFORMATION, "Internet Browser", "Connecting to Firefox ...", 2) _FFStart($myUrl, "default", 2);Force FF to open, if process not already open MsgBox($MB_ICONINFORMATION, "Looking for tab", "Switching to the tab ...", 2) If ProcessExists("firefox.exe") Then _FFTabSetSelected("Text here that is in the tab", "label");The text must match in the tab... Else MsgBox($MB_ICONINFORMATION, "Firefox", "Opening New Firefox Session ...", 2) _FFStart($myUrl, "default", 2);Force FF to open, if process not already open EndIf ElseIf Not FileExists(@ProgramFilesDir & "//Mozilla Firefox/firefox.exe") Then MsgBox($MB_ICONINFORMATION, "Internet Browser", " FireFox can not be found!" & @CRLF & "Closing ...", 5) CLOSEButton() EndIfDepending on where FF.au3 is located, you may have to change #include "FF.au3" to #include <FF.au3> FF.au3 is being included since it is throwing the error messages. __FFWaitForRepl ==> Error TCPSend / TCPRecv: TCPRecv :-1 __FFSend ==> Socket Error _FFCmd ==> Error return value FF is waiting for MozRepl, so it can't make the connection. I think this is key. I'll keep digging for the answer. We do need your code snippet though. I think the connection to MozRepl is timing out and FF.au3 is setting the errors. Still just a guess without seeing your code. Hope this helps...