I have macOS El Capitan on my Mac Pro and I am trying to update my Mac Pro to macOS High Sierra so I can update it to Mojave later since Mojave requires to have at least macOS High Sierra. But when I run the installer I get the below error. Any advice on the steps needed to overcome this issue?
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This is my Mac Pro specs:
![enter image description here enter image description here]()
This is my disks in Disk utility:
![enter image description here enter image description here]()

This is my Mac Pro specs:

This is my disks in Disk utility:
