This KB can be used to help you restore the signature tool in Bluebeam from those that report it being grayed out. Here are the steps you can follow to fix that issue:

  1. Close Revu if you haven't already closed it.
  2. Download the Safe.enx file attached in this KB.
  3. Navigate to the following directory: C:\ProgramData\Bluebeam Software\Bluebeam Revu\Year of Revu\Revu\Features. If you don't see a Features folder, create a new one by right-clicking in the folder and clicking New. 
  4. Note: ProgramData is a hidden folder. If you don't see it when you go to the C: drive, select the View tab and then enable the option for "Hidden Items". You should now be able to see the ProgramData folder.
  5. Copy the Safe.enx file into the Features folder.
  6. Reopen Revu and try again.