If a link on an emailed report subscription results in a "HTTP 404 error page not found" error, it's likely due to not being logged into the platform and switched into the correct Organizational level prior to clicking the "View Report" link.
This can happen if you are logged into the VMware Aria Cost platform at Top Level Organizational Unit (TLOU) FlexOrg but the report you are subscribed to was created at Sub OU level FlexOrg. Links for reports created under a sub organization don't work unless the user is logged in and have selected the sub-organization.
The email link will state which organization level it was created in:
Once you are logged in and authenticated with the platform, the link in the subscription email will take you to the specific report view you are expecting.