@firozstar, welcome to this community.
In this case, you just need to follow the message instructions!
Open the "Analysis settings" dialogs and set the amount to zero if you want to avoid the warning.
...but probably it is not a good idea!
From the documentation:
Limit trade size as % of entry bar volume
This prevents from entering the trades greater than given percentage of entry bar's volume. For example if backtesting daily data and today's volume for thinly traded stock is 177,000 shares, setting this to 10% will limit the maximum trade size to 17,700 shares (10% of total daily volume). This prevents from 'affecting the market' by huge orders.
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