Hi there, Arslan Latif.

Let’s try accepting these invitations through a private window. Here’s how to start browsing privately:

• For Chrome, press Ctrl + Shift + N.
• For Internet Explorer or Firefox, press Ctrl + Shift + P.
• For Safari, hold down Command + Shift + N.

If you’re able to accept invites through a private browser, it’d be best to clear your browser’s cache or switch to a different browser.  There are times that the overloaded files stored in your browser can cause the program to misbehave.

Let us know if you need anything else by posting here again.