For the record.
When running mpsvrrel64, this error comes GLIBCXX_3.4.21 required.
But on CentOS 7, GLIBCXX is upto 3.4.19.
From CentOS 8, it can be run.
Try download letest version of this linux
I tried In old versions and didn't work
I tested script update for Os I downloaded lastest version of this Linux and worked for me