|Just move the file to the root directory. Once you moved it you will be able to give it up to 256 characters. |
The 256 character (really 255 to be exact) counts the root directory letter followed by slash, colon, folder name, colon, subfolder name, and so on then finally the file itself. Be aware that any file with long file name (LFN) that exceeded the 255 limitation will be truncated.