Are you on Catalina using the VirtualBox virtual machine workaround for Screenwriter 6.5 or Dramatica Story Expert 5.3, or have you recently restored files onto a Mac using Time Machine? If so, that may be the cause of this system I/O error.
You MUST first be logged in as user that has administrator access. (if you only have one user / login on your Mac, then that account will be your administrator).
While in your Mojave VirtualBox virtual machine, download the attached file and unzip the file to the desktop. It will be called cleanup.command. Double-click the cleanup.command file to run, then follow the instructions that will be displayed.
Now try running Screenwriter or Dramatica Story Expert -- whichever gave you Error 105 message. If it works, please DELETE the cleanup.command script and the cleanup.command.zip archive. It should never be run EXCEPT by direction from us.
If this does not work, please create a support ticket and we will investigate your particular issue.