CANVAS WARN

[eoxyn]

[03:17:55 WARN]: [CanvasMC] Thread failed main thread check: Cannot init menu async, context=[thread=Folia Region Scheduler Thread #1,class=io.papermc.paper.threadedregions.TickRegionScheduler$TickThreadRunner,region={null}], entity={root=[{type=ServerPlayer,id=3740252,uuid=4dd1cef6-f971-36fd-9d87-d24100db71c4,pos=(715.879,87.500,-225.778),mot=(0.000,-0.078,0.000),aabb=AABB[715.5791344925021, 87.5, -226.07824883215412] -> [716.179134516344, 89.29999995231628, -225.47824880831226],removed=null,has_vehicle=false,passenger_count=0], vehicle=[{null}], passengers=[]
java.lang.Throwable
        at io.canvasmc.canvas.util.TickGuard.guard(TickGuard.java:48) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at net.minecraft.server.level.ServerPlayer.initMenu(ServerPlayer.java:921) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at org.bukkit.craftbukkit.entity.CraftHumanEntity.openCustomInventory(CraftHumanEntity.java:390) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at org.bukkit.craftbukkit.entity.CraftHumanEntity.openInventory(CraftHumanEntity.java:361) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.inventory.VInventoryManager.createInventory(VInventoryManager.java:119) ~[?:?]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.inventory.VInventoryManager.createInventory(VInventoryManager.java:73) ~[?:?]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.common.utils.ZUtils.createInventory(ZUtils.java:263) ~[?:?]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.ZInventoryManager.openInventory(ZInventoryManager.java:356) ~[?:?]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.requirement.actions.InventoryAction.lambda$execute$0(InventoryAction.java:55) ~[?:?]
        at zMenu-1.1.1.5.jar//fr.maxlego08.menu.hooks.folialib.impl.FoliaImplementation.lambda$runNextTick$0(FoliaImplementation.java:96) ~[?:?]
        at io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler$GlobalScheduledTask.run(FoliaGlobalRegionScheduler.java:178) ~[canvas-26.1.2.jar:?]
        at io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler.tick(FoliaGlobalRegionScheduler.java:36) ~[canvas-26.1.2.jar:?]
        at io.papermc.paper.threadedregions.RegionizedServer.globalTick(RegionizedServer.java:360) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at io.papermc.paper.threadedregions.RegionizedServer$GlobalTickTickHandle.tickRegion(RegionizedServer.java:203) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at io.papermc.paper.threadedregions.TickRegionScheduler$RegionScheduleHandle.runTick(TickRegionScheduler.java:524) ~[canvas-26.1.2.jar:26.1.2-866-f0d763a]
        at ca.spottedleaf.concurrentutil.scheduler.EDFSchedulerThreadPool$TickThreadRunner.run(EDFSchedulerThreadPool.java:528) ~[concurrentutil-0.0.10.jar:26.1.2-866-f0d763a]
        at ca.spottedleaf.concurrentutil.util.LazyRunnable.run(LazyRunnable.java:25) ~[concurrentutil-0.0.10.jar:?]
        at java.base/java.lang.Thread.run(Thread.java:1474) ~[?:?]

[duckducktw]

Same crash we hit on Canvas 26.2 with zMenu (1.1.0.5/1.1.1.6) — Cannot init menu async from TickGuard.guard().

Cause: zMenu's Folia hook (FoliaImplementation.runNextTick) opens the inventory from the global region scheduler, but ServerPlayer.initMenu must run on the player's own region thread. Upstream Folia only warns; Canvas' TickGuard throws.

Temporary workaround (tested on Canvas 26.2): https://github.com/sunrisemc-tw/canvas-folia-guard-remover
A JVM agent that strips the 3 async guards (Cannot init menu async / Cannot close container async / Cannot trigger criterion async) at class load. ⚠️ It disables Canvas' async protection entirely — not a safe fix, use at your own risk. Your stack is 26.1.2; same guard path, but I've only verified it on 26.2.

The real fix belongs in zMenu: open inventories from the player's region scheduler instead of the global one.

[1robie]

Try with zmenu 1.1.1.7 that should be good