title: "you can't perform that action at this time" error when using github GUI to pull and merge
body: <p>Hello i got some issue when i try to do the pull request in github.</p>
  
  <p>This is the step2 that i did before i do pull request :</p>
  
  <ol>
  <li>i create my localbranch ( git checkout -b exampleBranch )</li>
  <li>i make some changes.</li>
  <li>i save it in stash </li>
  <li>i request pull in GIT Bash ( git pull origin myBranch )</li>
  <li>i use git stash pop to get my changes back.</li>
  <li>i add, commit and push to my exampleBranch</li>
  <li>i go to gui github to pull my exampleBranch ( pull and merge)</li>
  <li>and when i tried to pull it. I got error information, it says "you cant perform that action at this time"</li>
  </ol>
  
  <p>i tried to search it in google, and i already disable all of web extension ( i dont know if this step is related to this issue )</p>
  
  <p>i dont know if anyone has same issue as me.</p>
  
  <p>I really appreciate for those who want to participate to help me solve this issue.</p>
  
  <p>kindly see the attachment.</p>
  
  <p>*Sorry for any grammatical mistakes
  <br>Before
  <a href="https://i.stack.imgur.com/XZm64.png" rel="noreferrer"><img src="https://i.stack.imgur.com/XZm64.png" alt="Before Request"></a>
  Error massage. 
  <a href="https://i.stack.imgur.com/Ve8wX.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Ve8wX.png" alt="Error msg"></a></p>