Quick answer: Set a floor max angle that includes your slopes, enable floor snapping, and use move_and_slide with up direction set so the character walks slopes smoothly.
A character stuck on slopes usually has floor settings that treat the slope as a wall. Adjusting them fixes it. Here is how.
How to fix it
1. Raise the floor max angle
move_and_slide treats surfaces steeper than the floor max angle as walls. If your slopes exceed it, the character cannot walk up them. Raise the angle to include the slopes you want walkable.
2. Enable floor snapping
Without floor snapping, a character can bounce off or lose contact on slopes going down. Set the floor snap length so the character stays glued to the ground across slope changes.
3. Set the up direction
Pass the correct up direction to move_and_slide so it can distinguish floor, wall, and ceiling. A wrong or missing up direction makes slope handling behave erratically.
Catching the ones you can't reproduce
The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.
Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.
This is where a tool like Bugnet earns its place. Its SDK captures every Godot error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.
The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.