This warning occurs when a function with no parameters is called by passing parameters. %s - Function Name.
Make sure to pass parameter only when parameter is required by the function. Either remove the parameter passed or specify 'parameter' inside the function as applicable.
Example
[#Menu:Gateway of Tally]
Add: Button: MyButton
[Button: MyButton]
Key: Alt+F9
Action: Call: MyFunc:"abc"
[Function: MyFunc]
000:Log: "In"
In the example, the function 'MyFunc' has no parameters is called in button by passing a parameter, hence the message warning T0020:The function 'MyFunc' - does not take any parameter appears.
The code is corrected by passing the required parameter.
[#Menu: Gateway of Tally]
Add: Button: MyButton
[Button: MyButton]
Key: Alt+F9
Action: Call: MyFunc
[Function: MyFunc]
000:Log: "In"