I get that error all the time. Look for a bottom row button that's sitting in no man's land between DMAIN and PHEADER. In other words, on your DMAIN panel you have all these buttons (Accept, Cancel, Delete, OK, Printer, Help, Print Order, etc). One or more of them is not aligned with the rest. Look at this screenshot. You'll see that BT_HELP is in no man's land I get the same error as you. If I put it back next to the Printer button all is well.