title: Source code string cannot contain null bytes
body: <p>So i had 676 line program, Now i have had a issue in the past when I opened the file all my code had disapeared so this time i made a backup. However when I try to copy and paste my backedup code then run it, it gives me this syntax error:</p>
  
  <pre><code>Source code string cannot contain null bytes
  </code></pre>
  
  <p>This was not displayed when I first made the backup and the program was working fine. I really do not want to go through 676 lines redoing it all. 
  Im a pretty basic programmer when it comes to Python. </p>
  
  <p>I already tried removing all white space and comments/# (Red background colour is at the end of a #)
  Already looked through all the code and it really has no errors.</p>