Shopware 5 Error 403

[ManiMAK]

Dear Community,

since yesterday we cannot receive payments through our shop. the error on backend is as follows:

An error occurred: Client error: `POST https://api-m.paypal.com/v1/oauth2/token` resulted in a `403 Forbidden`

nothing changed from our side. 

Also on frontend cannot connect to PayPal.

pls help.

thx

Manfred