For newest versions, the reader is only compatible with flash versions.

To get a local copy you need to download "base" and the versions you want to be able to use.
For newest tibia versions you need newest "base" so just download it again.

Go to online Tibia Dat Reader (7.0, 10.77, 10.78, 10.80, 10.99, 11.10, 11.31)

Download "base" updated for 11.31
Compressed versions are hosted here:!QlQ13QbD!XhYKL8bMw-qOrXZ6OuSYrA

How to add new versions to the dat reader (if the dat format doesn't change)