5D Mark IV Firmware Update Issues

[Grand4]

I have been trying to put the firmware update on my 5D Mark IV. I've downloaded the firmware for Mac onto a 128 GB memory card and a 64 GB SanDisk. I've put the cards in the camera separately and together.  I get the same message of "Memory Card containing firmware is required to update". I've also tried using M and P modes to see if that will get it to work. Any ideas would be greatly appreciated.  

[Waddizzle]

What is the file extension for the name of the firmware file?  It should be FIR. Only use one memory card during an update.

[Peter]

If the firmware is 1.4.0 there is no need to update to 1.5.0. because that version removes features due to a EU decision.

[Grand4]

Thank you for responding. When I opened  the memory card I got a message from Adobe Acrobat Reader saying it couldn't open 5D400140.Fir because it's not a supported file type or the file was damaged. I changed memory cards and I get the picture of a download that says eos5d4-v1401mac-c.dmg. The camera says there is no firmware on the card. 

[Grand4]

Thank you for the information about 1.5.0 but I'm trying to update from 1.2.1to 1.4.0

[Grand4 · Accepted solution]

I found the solution on the Adobe website. I had been putting the download on the Memory card. That loaded the PDF instructions too. Adobe said to drop the .fir file from the Finder window onto your SD Card to copy it there, and then look at the PDF for instructions to update. Thanks again for your time in trying to fix my update problem.