Getting a 400 Session Invalid Error When Trying to Connect Instagram?

Getting a 400 Session Invalid Error When Trying to Connect to Instagram?

This error is one of the most common connection issues users experience when logging into Instagram to join a campaign.

That "400 Session Invalid" error is essentially Instagram’s way of saying, "I know who you are, but I don't trust this handshake." It usually happens when the security token between your device and their server gets corrupted or expires.

1. The "Refresh" Tactics (Start Here)

Sometimes the session is just "stuck." Try these in order:

Log Out and Back In: Don't just close the app. Go to your profile → Settings and Activity → Scroll to the bottom and Log Out. Then, log back in manually.
Force Restart the App: Swipe up from the bottom of your iPhone 14 screen, hold in the middle, and swipe the Instagram window away completely.
Switch Your Connection: If you're on Wi-Fi, switch to Cellular (5G/LTE), or vice versa. Sometimes an IP address change forces a session refresh.

2. Clear Browser Data (The Secret Culprit)

Even if you're using the app, Instagram uses an internal "In-App Browser" that stores cookies. If those cookies are stale, you get the 400 error.

Open Instagram and go to your Profile.
Tap the three lines (Menu) → Settings and activity.
Scroll down to Website permissions → Browser settings.
Tap Clear next to "Browsing data."

3. Disconnect Third-Party Apps

If you are getting this error while trying to connect Instagram to another service (like Canva, a scheduling tool, or Facebook), the old "link" is likely broken.

On Instagram: Go to Settings and activity → Website permissions → Apps and websites. Remove any "Expired" or "Active" apps that you are currently trying to connect. Then try the connection again from the other app.

4. The "Nuclear" Option: Password Reset

If nothing else works, changing your password is the most effective way to kill all invalid sessions.

Changing your password forces Instagram to terminate every single active session (including the "invalid" one) and issue a brand-new security token to your device.