Is this in the dashboard or from a block editing dialog?

it's within dashboard. code or, better to say, error is caught when i try to click on already uploaded images to edit them, but nothing happen

Very strange. Where exactly does this error show up? In the popup menu when you click on the thumbnail? Or does the entire screen turn white with the error message in black text? Or something else?

Also, are you using one of the built-in themes or did you download one from the marketplace (and if so, which one)? Did you customize either of those in any way? Or did you build your own theme from scratch?

in fact it's displayed in my chrome developer console probably =] otherwise, i have some plugins installed and but uninstalled everything afterward i realized this ... no effect
i can make a user for you on my website and u can take a look for yourself

otherwise if you can discover something unless you get logged in u can try wp3.netport.cz

Sorry, I don't have time to look into this in more detail. Wish I had a better answer for you :(