Hi @JColvin,
First of all, thanks for your quick reply. I saw that especially for Zybo Z7-20 for the specific BSP on Digilent repositories it needs Vivado 2017.4 and Petalinux 2017.4. I have these. Plus, I tried building a different BSP on Petalinux Download page and it is also a success.
Hopefully, I tried the answer at the bottom of this page: https://forum.digilentinc.com/topic/22300-petalinux-build-build-getting-failed-for-cora-z7/ and it worked, but till some point. Yet, I am having this error now:
| *** Can't find default configuration "arch/../configs/zynq_zyboz7_defconfig"!
Is there a straightforward way I can fix this as well?