If you try to access the file share of the VMM Library Share from the Management Server you might encounter the below exception. I have seen the behavior in SCVMM 2016 and SCVMM 1801.
It is strange as I am logged in as an administrator(DOM50446Administrator) and I installed VMM Management Server with the same account.
Now when I access the share from windows file explorer, I encounter the same problem.
Interestingly, if I access the file share from another machine with the same account, I can access the share. I do not remember why I tested it 
I tried to locate the folder in my VMM Management Server and after some struggle I am able to locate it under C:ProgramDataVirtual Machine Manager Library Files.
Looking at the permissions of the share, I can see "Domain Admins" group has full control, which explains why we can access the share from other machines.
Just for the sake of checking, I verified the account DOM50446Administrator is a part of the group "Domain Admins".
I explicitly added the account DOM50446Administrator to the permissions and gave Full Control.
And now the Library Share is accessible from the VMM console.
At this point of time, I do not have any idea why this behavior is seen. May be once I can talk to a Windows Expert I will get the answers to my questions :). And I will update the article with the root cause.
This is environment specific and I am not sure how I landed up in such a situation.