General information:
On the english Wiki you can find a lot of information about how a QR code work.
In a raw QR code the "bits" are black for 1 and white for 0.
But thats not the case in the finished QR code.
If you get to many white/black areas it can be hard to scan.
To fix this problem a mask is applied to the bits to make it more readable.
In specific parts of the QR code the scanner can read what mask patton to use.
For reliability this information are stored two places in the QR.
One place to identify the mask are these 3 bits (marked with green).
111 correspond to mask 2 (j % 3 = 0).
The wherigo needed to find the cache.
How to find the cache:
On https://tirsdagsklubben.rocks/GCB6WTG/<Data from the Bad QR>/ you can find the coordinate code that you need for the Wherigo game.
But first you need the data from the bad QR.
You can get a clean 2 color png version of the bad QR here:
https://tirsdagsklubben.rocks/GCB6WTG/BadQR.png
(QR21x21, 210x210 pixel, each bit 10x10 pixel)
You might notice that the Bad QR show mask 2 (j % 3 = 0), but no mask was appiled!
You task is to get the QR code from the url, add a mask 2 (j % 3 = 0) to the databits to make the QR readable, read it and insert the data in the url. Then use the given coordinatecode in the Wherego game.