When I launch it shows up the logo then closes. If I turn off my internet it launches in offline mode.
btw I only use windows defender.
There isn’t a known fix for this. You can try general fixes but it might not solve your issue.
The most recent case of a user having your issue is @Naeemo (unsurprisingly never got solved). They of course felt they needed to split the discussion into 4 threads so I won’t be able to post links (too time consuming on mobile). Click the name and look at the threads, you will find some good info.
You aren’t missing anything by being offline unless you have a paid diamond subscription. The showreel of editors in the top will miss a few editors but everything will still be available in the program when you open the file.