If you tried with https://jonmifile.com/help-center/royalbot/common-issues/white-screen-loading-seafight-page/ and it didnt worked, you should try this tutorial also:

1. Close all RoyalBots.

   It is very important to close all bots before. Check it.

2. Press Start Button (Windows) and type CERTMGR.MSC

   
   Now click the application and it will open.

3. Go to Personal -> Certificates

   Navigate to this section.
   

4. Delete DO_NOT_TRUST_FiddlerRoot certificate

   Look into the list for this certificate and delete it.

5. Go to Trusted Root Certification Authorities-> Certificates

   And repeat STEP 4. Delete DO_NOT_TRUST_FiddlerRoot certificate.

6. Now open RoyalBot

   A windows will appear asking for a certificate install. You have to press YES.
   
   

7. Done

   Now RoyalBot should work properly.