With no Vulkan GPU, the bundled Lavapipe software renderer lets the editor open. It is slow by design.
Windows will not run the portable build
Unpack the whole .zip first, then run Launch-Editor.bat from the unpacked folder. Running it from inside the archive fails.
Things on screen
My sprite is invisible
Does the SpriteRenderer have a Texture or a Color with alpha above zero?
Is the entity inside the camera's view? Select it and press F to frame it.
Check the Camera2D: OrthographicSize too small can leave the object off screen.
Another sprite may cover it. Compare SortingLayer and OrderInLayer; a higher value draws on top.
The sprite looks stretched
Check the entity's Scale in Transform2D. Use FlipX / FlipY to mirror a sprite, not a negative scale.
My text looks wrong on one phone
UI text uses MSDF rendering and stays sharp at any DPI. Check the RectTransform anchors and your Canvas mode (ScreenOverlay for HUD, WorldSpace for floating elements).
Physics
Objects fall through the floor
The floor needs a collider and a Rigidbody2D set to Static. A collider without a body, or a body without a collider, is not enough.
Very fast objects can skip a thin wall. Turn on Bullet (CCD) on the fast body's Rigidbody2D.
My character tips over
Turn on FixedRotation on its Rigidbody2D, which is standard for platformer characters. Consider a CapsuleCollider2D.
Nothing happens when I touch a coin
The coin's collider must have Is Sensor on, and your script needs public override void OnTriggerEnter(Entity other). Both objects need colliders, and at least one needs a Rigidbody2D.
Gravity pulls my top-down game
Set GravityScale to 0 on the Rigidbody2D.
Scripts
My script does nothing
Is it attached to an entity in the scene?
Does the class name match the file name, and does it inherit from Entity?
Open the Console. A compile error blocks the script. Double-click the message to jump to the line.
A field does not show up in the Inspector
Only public fields are exposed. Make it public float MoveSpeed = 6.0f;.
GetComponent returns null
The entity does not have that component. Add it in the Inspector or with AddComponent<T>(). Look components up in OnAwake, and check for null before using the result.
Changes to my script do not appear
On desktop, save the file. Hot reload picks it up within seconds. Check the Console for compile errors.
Saving
I lost my scene changes
Save often with Ctrl + S, and turn on auto-save in Editor Preferences for crash recovery. Make edits while the game is stopped, not playing: changes made during Play are discarded when you stop.
A texture came up empty after I moved it
Move and rename assets inside the editor so the .meta ID and every reference stay linked.
Android
My phone is not found
Turn on Developer options and USB debugging, accept the prompt on the phone, and try another cable or port.
For Wi-Fi, pair first, then connect, and keep both devices on the same network:
The engine opts into high refresh rates on devices that support them, such as flagship Samsung, Pixel and OnePlus phones. Devices without support stay at their normal refresh rate.
The back button or gesture does something odd
Back events are routed to Application.OnBackPressed. Handle that in your script. See Android export.