I encountered a problem when using VirtueMart since an error stating “Error: You do not have permission to access the requested Module” kept appearing to the user when trying to check out with payments. When searching for the proper solution, I realized a lot of people had the same unresolved issue, and by that I mean toooo many people.
I found various answers why this may happen. If running on a personal server, installing an apache server such as XAMP may solve the situation, other cases said that if logging in on that page, will make the message disappear.
Solution to the problem:
Well I found a simpler solution. I modified some changes in the Module List and the error disappeared completely. To access the Module List, Log in to the backend, access the VirtueMart, Admin and Select Module List from the left side menu. A list which all the options will appear and some alterations need to be done. Uncheck Admin, StoreAdmin, Shopper and select None for the following options: store, msgs, shop and checkout.
That should do the trick!
P.S: the below image shows how the modified modules need to be set: