Hello muna325 and welcome to Apple Support Communities.
Thank you for posting in the Apple Support Communities. I see no one has responded to your post yet. To assist the community in replying, you might consider providing more information about what you’re experiencing. Including the following details in your post may be helpful:
What device is this happening with? Which software version?
Is the person who sent the calendar invite in your Contacts app? Is their contact info complete and correct?
If this is on a Mac, try a safe boot to clear caches and give you a solid foundation for additional troubleshooting.
Use safe mode to isolate issues with your Mac - Apple Support
The more information you provide, the better chance the community will be able to offer some additional guidance.
Have a great day!