What is wrong with my excel formula syntax?

I have made several formula to dynamically create a SQL query but to make it perfect, I want to add a condition : "if cell is not blank".

I've tried a lot of different syntaxe but even with a very simple one (see exemple below), I get an error.

My formula is :

="""" & SUBSTITUE(E2;"'";"''") & """"

It works well and give me "Accordéoniste d''hier"

I've tried

=IF(E2<>"";"""" & SUBSTITUE(E2;"'";"''") & """";"")

Excel display #NOM? in the cell but doesn't give me an explicit error.

I've tried a very simple one, but I get the same result : #NOM?

=IF(1=1;"Delivered";"")

I've tried ISBLANK but same result... I think there is something wrong and I don't see it...

Thanks for your help !