Getting the {"error_type": "OAuthException", "code": 400, "error_message": "Session invalid"} while trying to log with instagram from Creator Studio

Hello !!

I’m not a programmer, but just a desesperate girl that trying to fix a problem ^^

I’m stuck since 4 days now, even concierge assistant from facebook haven’t be able to resolve it. When i want to connect my instagram throught Creator Studio, I got this error :

{“error_type”: “OAuthException”, “code”: 400, “error_message”: “Session invalid”}

Here are the different steps I did : clean my cookies and cache, disable all the third party extension, try in different navigator as google, safari and firefox and my phone. Disconnect myself from facebook and then try to log… I have no solution… At least, I would love to understand what’s this error message mean… but now i’m stuck and I don’t know why
Your help and knowledge on this forum would be welcome