panel builder 32 error code 9077

I am adding to a current application and keep getting error code 9077 when i try to validate the changes I have made. I added a maintained push button with the tag address I:40/06 I can make it work by changing the address to I:41/06 or higher but I do not understand why it will not accept I:40/06. the error states. Error 9077 - Address overlaps Block Transfer/Pass-Through Control Byte
Problem
You entered a tag with the same address as the Block Transfer Control Byte. The Block Transfer control byte is always the lowest accessible byte in the discrete rack.
Solution
Do not assign this tag to an object. Re-assign the tag address. Disable block transfers, if used.

Those addresses are reserved for the block transfer control process. The explanation in red in your post is pretty clear about what is happening.

Perhaps you want all the nitty gritty details?

The help files in PB32 have quite a bit of information, but don't tell us exactly what each bit is used for in the control block. I think the information is available somewhere, possibly on the knowledgebase at ab.com.

Find where your other push buttons are located within the block hiarchy and put it in that location. Sounds like the PV is doing a block transfer starting with I:40 which means the low side I:40/00 to I:40/07 is reserved for internal use. Why are your particularly wanting I:40/06?

The reason I want to use I:40/6 is because the plc I'm interfacing w/ is a plc 5 and this particular instruction is used a couple hundred times in the program. I can use a different input but I will have to edit the plc program everywhere the input is used.

So your replacing a hardwired switch with a digital and the pv doesn't like the address even though the PLC5 is okay. If you can just hook up with the PLC, save the file, go offline, then do a Global replace with description move to an available Input that works for both the PLC5 and the PV. Finally when they are shut down, upload the change to the PLC5 and you should be able to update your PV as well. When they start back up tell them to check thier settings, in case they changed over during the time between download and upload, if your process had changes.