Veeam One and vCenter 5.5 Update 3
If you are using Veeam One 8.0 and has updated vCenter to version 5.5 update 3, you will get an error that it can't collect performance data.
This i due to a change in vCenter that limits the query size.
Veeam has a hotfix to solve this problem Veeam One Build 8.0.1731: https://www.veeam.com/kb2071