The 1.6 update completely ruined this mod.
I play in 2 places; one is a plugin-heavy multiplayer server, the other my friend's vanilla Realm. On both I use this mod as well as the Minimap mod. On both the realm & the server, the update to 1.6 completely reset my world map, erasing all exploration I've done. But they were also each messed up in different ways.
On the server I don't use waypoints much because we're not to use player-side mods to teleport. But there is a server-plugin command that players use to teleport which I use constantly, and every time I do I get a big message across my screen telling me to press RIGHT SHIFT because "World Map needs confirmation" (whatever that means). It's not a game breaker or anything but it's annoying as hell to have to do every single time I teleport.
On the Realm it is much worse. I've lost access to ALL of my waypoints. None of are showing on my world map anymore (not even the ones in the area around me, which is the only area showing as explored on my map now). When I open the waypoint menu, under "Sub-World/Dimension" there's a drop-down menu where there are now 2 Overworld's listed, and all my waypoints are in the 2nd Overworld rather than the first/auto one. When I select the world with my waypoints, they show up in the world itself, but still not on the world map. And when I click on them in the list, the teleport option is disabled. So I can no longer see OR access any part of the world I've explored & labeled before. I'd have to start over from scratch, re-exploring the world and rebuilding a new network of teleport waypoints.
This has left me no choice but to go back to using WorldMap 1.5.7 and MiniMap 20.11.0 (good thing I've kept copies of every mod file I've downloaded for just this reason!). I don't think I will bother trying any newer versions of these mods at all until it's for Minecraft 1.16, and even then only if the above problems have been fixed.