Cannot drag sharp symbol from template to the score

It sounds like you are trying to add a picture to a text. Simply type the # sign instead. :)

If what you are referring to is a 'D/F#' chord name written above the staff on a lead sheet, you don't have to 'drag' the sharp symbol. When you type in chord names, use the '#' key (above the '3' key) for sharps. So you would type 'D' followed by '/', followed by '#' (shift + 3). For flats in a chord name, like Bb7, type the letter 'b' to enter a flat.

As mentioned, chord symbols are produced by simply typing - no drag and drop is required. You might want to check out my lead sheet tutorial; it will probably answer a number of questions you might otherwise have:

http://musescore.org/en/node/11723

Also, don't try using drag and drop for accidentals on notes, either. Just use the arrow keys. The tutorial videos on the main musescore.org page are great resource for learning how to do basic things.

As mentioned, chord symbols are produced by simply typing - no drag and drop is required. You might want to check out my lead sheet tutorial; it will probably answer a number of questions you might otherwise have:

http://musescore.org/en/node/11723

Also, don't try using drag and drop for accidentals on notes, either. Just use the arrow keys. The tutorial videos on the main musescore.org page are great resource for learning how to do basic things.