This message occurs when the PrecisionTree Launching application, PTREE.EXE, is unable to tell Excel to open PTREE.XLA, the main PrecisionTree add-in file. The most likely reason this occurred is because Excel's Ignore Other Applications option is turned on. Boot Excel (without PrecisionTree). Select the Options menu item from Excel's Tools menu. On the dialog's General tab, there is an option called Ignore Other Applications. This option must be turned off for PrecisionTree to work properly.
