MT4 not Loading the EA Because Variable

[Quinttin]

Hi Admin.

i create a EA. I put a Condition with Candle close on the on the first and its Greater than 50 SMA. But i need the Distance of this. I put The Command P3-P1 on it , But when i Opload the Mt4 i got a message that Mt4 can not load the EA

https://gyazo.com/5d9b1f894da2780aac1e964eb2f8d558

Why is this an Issue?

[fxDreema]

I will check, but people prefer to use "Formula" block for such small operation