Audi A4 - AdBlue Warning

[donkman]

Hi,
We recently bought a used Audi A4 Quattro 2016. The other day, we filled up with AdBlue from a gas station.
After that, the system showed a warning roughly (in another language): "AdBlue: The motor cannot be started after 75000 km. See the instruction book".
The instruction book states that the warning could be caused by another fluid other than AdBlue having been filled or by an error in the system.

My question is whether there is a known fix I could do or whether a workshop is needed.

Thank you!
 

[Magnet]

Hello Joel,

Have you searched and read the numerous posts on here on this topic? 
Kind regards,

Gareth.