External Storage - SMB/CIFS WS2012R2

I am trying to configure Nextcloud external storage for Windows Server 2012 R2. But when setting the folder in C: \ on windows server, everything works.
When setting the folder to D: , E: \ sharing gives error.

Ncp: 17.0.1
O.S. Debian 9
PHP 7.2
SMB Client: 4.5.16-Debian

Windows Server 2012R2

*I already searched the community but I didn’t find a solution.

thanks for the support!

best would be you’d try to find the difference between drive c on the one hand and drives d and e on the other hand.
like are d and e mapped networkdrives, e.g.?

All drives are disk, unmapped, or networked
Could it be something related to both system (nextcloud and WS2012R2) being a VM and being on Hyper-V?

it really COULD be. please go ahead trying to narrow the problem down. it seems to be important.