Hello, dear friends, how are you? I hope so!

I have a problem similar to the one reported in this blog.
I have a project that has 2 PLCs and 2 HMIs (TIA V15.1) of machines that communicate with each other.
The backup of the project provided, PLC_1 is complete and correct and identical to the online program. However, PLC_2 has firmware 4.2 and the online program is in firmware version 4.4.1. I would like to know how to solve this if I do not have the backup with the two correct programs.

Do I need to update TIA V15.1 with the firmware?

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Split from 6ES7 217-1AG40-0XB0 v4.4.1.