To check whether a player is active, first enter the player link:
then click:
Link style: Lords & Knights (default) Xmas edition
(T-C!p)
Lords and Knights and the XMas edition of Lords and Knights use different styles of links. The two applications are otherwise identical except for cosmetic differences.
Lords and Knights uses links that look like l+k://... whilst the Xmas editing uses links like lkxmas://...
Selecting the wrong one and the links either won't open for you or if you have both apps installed then it will open in the wrong one.
We report a player as active if we can see some change (capture a castle, develop a castle, rename a castle, join an alliance, etc), and inactive if there is no evidence of the player being active.