
Have you installed CU before?
Please clear browser cache or try to open it in another browser.
And you could provide ULS logs or Fiddler logs to further troubleshoot.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.