I am completely new to IIS and would like to host a website with a virtual directory. I've got a working website A with domain https://mydomain.lan:3002, hosted using IIS in C:\inetpub\wwwroot. I would like to serve PDF files from outside this webroot, namely from a network share located at \\mynetworkshare\pdffiles, mounted as Y:\.

Website A is created in IIS Manager right under "Sites". I added the virtual directory, pointing to the mounted folder, aliasing it as pdf. I can browse the virtual directory under pdf in IIS Manager just fine.

When I want to access these files using the website (https://mydomain.lan:3002/pdf), I get 500.19 - Internal Server Error. What do I need to do to make it work?