what does this error mean "Expression evaluation error : Invalid index: Cannot index property 'data' of type Text into type List of Variant"?

Can you provide further context, like what you're querying and where you're later attempting to refer to the query result?  Going by only what I can see here, i'd have to guess (and my guess would be that your query is returning an empty set, not even a datasubset, and you're attempting to refer to a nonexistent ".data" property within it).

Thanks Mike, I'm simply trying to retrieve data from datasubset using queryentity and I got the issue is with it returning empty set. But why it refers ".data" property as "text" in the error which is of "dictionary" type.

I'm not sure why, but from experience I know that this error language is typically seen when trying to reference a dot property into a dictionary that doesn't contain that property.  This is why it would be helpful to get some more context as to your query and the interface in which you're trying to use it.

Hi rajeshs0004

User is trying to access data field from a null dictionary structure. Have a look to below two variables:

a!localVariables(
local!dictionary1: {
data: null,
pagingInfo: null
},
local!dictionary2: {
null
},
local!dictionary1.data
)

Here if user access .data from "local!dictionary1" then it will work as it has defined structure with null values where as it won't for "local!dictionary2" as structure itself is null.

Looks like your scenario is similar to local!dictionary2. 

Hello,

You should first try without the .data, then make sure that you are retrieving a dictionary. I personally prefer to use the .data in the calls rather than inside the Query Entity expression rule.

As said before in this chain, this issue occurs with the "." call. Best is always to use index(pv, "field",null), so instead of giving you an error, you get a null value.

Thanks evryone for the help, got the point...