Last friday I bought a laptop and installed my Lightroom C6 on it. Because I was not satisfied with that laptop, I deleted LR6 and returned it to the shop.
I bought another laptop. On that other laptop I installed LR6 and then there was a message that the limit of active computers was reached. I think this is caused by not deactivating LR6 on the laptop I returned. I then did not know I had to do that.