You may find that end users are receiving the following message when attempting to download/install Visio or Project from the O365 Portal.
Visio
Install Visio
Your admin has turned off Visio installs. Contact your admin for more information about how to get Visio in your organization.
If this is unexpected and users should have access to download Visio/Project, check the Software Download Settings from within the Admin Portal.
1. Open the Office 365 Admin Center Home page. (https://portal.office.com/adminportal/home#/homepage)
2. Under the 'Office Software' tile, select 'Software download settings'
3. You may find that Visio/Project are already set to be available for download, if so, toggle the setting to Off, then back On.
4. It may take some time for the change to be seen in the Portal download page.