Thanks for reaching out. If I understood you correctly, you are looking to collaborate with your colleague? If yes, please try the steps suggested here: https://helpx.adobe.com/xd/help/collaborate-coedit-designs.ug.html
Let us know if this helps or if you need any further assistance.
I have followed the same instructions but showing the same issues
*Thanks & Best Regards,*
*Manoj Yadav *
<Personal Info Removed by Moderator>
Could you please try re-inviting the user and check if it works or not. If it still doesn't work, please ask the collaborator to sign out of the Adobe CC Desktop app and from XD and then sign in again and please ensure that XD is signed in with the same email address which is added while inviting.