Problems after changing default product name lenght in presta 1.5.6.1

[woodland]

Hello,

 

I've changed default product name length to 255 (was 128) in classes/Product.php and in database. Unfortunately now, when I try to upload a photo to a product that has >128 product name lenght I'm receiving an error: undefined and 

SyntaxError {stack: (...), message: "Unexpected token <"} fileuploader.js:1099

Everything is fine if the product name is shorter than 128 characters. What else I need to change to fix that problem?