Hi there,
I see that you are trying to troubleshoot file share access issue on Windows 2012 R2 Server. Windows uses SMB protocol for file sharing and 2012 R2 is SMB 3 enabled. Is this a DFS file share or normal SMB share? Have you deployed the file share in a high availability cluster? What is the operating system of the client machine from where you are trying to access the shares hosted on 2012 R2 server? Is the connection across a WAN link or is the client and server located in the same network? I can help troubleshoot this issue and ensure the file share access works fine.
I'm a 7+ year experienced IT professional with a great understanding of on-premises (Windows) and Cloud (Azure) technologies. I've assisted multiple customers with deployment, migration, troubleshooting Windows and Azure environments. My primary skill sets include, but are not limited to Windows Active Directory, ADFS, Azure Active Directory, Windows Networking, Intune, PKI. Please take a look at my profile where I've listed the technologies I'm well versed at - https://www.freelancer.com/u/Gokulakshman
Please ping me so that we can have a quick discussion.