Shouldn’t this be:
BLYNK_WRITE(V21) //Function Mode 1
{
int Mode1 = param.asInt(); //Get value from Button V21
if (Mode1 == 1) { //if it is HIGH
varMode1++; //count the flag “varMode1” ++
}
if (varMode1 == 2) { //if the Button get pushed a second one
varMode1= 0; //flag “varCentralOut” is again 0
}
As Mode1 will never be 2 if the button is sending 1 and 0
No mode1 is only the status from the button. I know it can be only 1 or 0… if this button is clicked I sai to the variable varMode1 count on. By the first click it counts to 1. By the second click it counts to 2, but immediatelly after I say if varMode1 == 2, varMode1 = 0. So it can begin from new
Yes, but your if statement is looking for Mode1 to be equal to 2.
No, it says
Or am I missing something here…
Sorry there was an error by my side, that happens if you code on blynk website. 
But also if I write it like you, and also in my sketch it does not work. My question: How to compare two variables? There must be the error because in serial monitor I see if I click on Button from Mode 1 that varMode1 == 1 and the same also with the Button centralOut. But I never get the varLedOutput == 1. It remains usually 0. Tomorrow I will copy my original sketch here. 
Thx. in the meantime
I checked your past posts and you are using the wrong character in code formatting…
Do not use the tilde character, use the backtick character… same key, different character 
And don’t forget the cpp at the beginning.
