Hello!! I received a pdf file that can´t be ungrouped... It's kind of blocked... I can´t work with its elements separately... help!!!
I´m working that document in Illustrator
Just in case you haven't already tried this, many PDFs will open within Adobe Illustrator with all elements on the page held inside one or more clipping masks. The clipping masks, clipping groups, masks inside of masks, etc have to be released in order to edit the objects. Go to the Object menu and go down to Clipping Mask>Release. Or press the Ctrl+Alt+7 keyboard shortcut (Command+Option+7 on OSX) to do the same thing.
Another trouble shooting idea: check the layers palette for locked/hidden objects and layers.
It's probably just linked. You need to select the page and embed it. Then check the clipping masks and stuff.
Also: don't expect everything in a PDF to be editable. PDF was never meant for editing and Illustrator is not a general prupose PDF editor.