I am new to the platform and working on a better understading of the api. I am trying to build a modified version of the EMA universe selection algo. 

Instead of using the on securities change method, I want to set the Universe Resolution to minute data so I can rebalance only positive profit positions every 60 minutes for example. Although I am using minute data to capture intraday asset price movements for rebalancing I would like using Daily indicators. Not sure if I am going about this correctly.

I am using some code from the bootcamp and also searched the forums. I am stuck with code below. I am getting the errors below, also not sure if my my code is using best api practices.

Backtest Handled Error: CBLI TKH7EPK7SRC5: The security does not have an accurate price
as it has not yet received a bar of data. Before placing a trade (or using SetHoldings)
warm up your algorithm with SetWarmup, or use
slice.Contains(symbol) to confirm the Slice object has price before using the data.
Data does not necessarily all arrive at the same time so your algorithm should confirm
the data is ready before using it. In live trading this can mean you do not have an
active subscription to the asset class you're trying to trade. If using custom data
make sure you've set the 'Value' property.