What causes the “texture is not readable” exception in Unity?

Code calls GetPixels , EncodeToPNG , or similar on a texture whose importer has Read/Write disabled, so the CPU copy of the pixel data does not exist at runtime.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix “UnityException: Texture 'X' is not readable” in Unity

Quick answer: Enable Read/Write in the texture's import settings if you truly need CPU access, or avoid the CPU read entirely by blitting into a RenderTexture and reading that.

By default Unity uploads textures to the GPU and discards the CPU copy to save memory — and any pixel-reading API then throws this. You either opt in to a CPU copy or read via the GPU. Here is how to choose.

How to fix it

1. Enable Read/Write for genuine CPU work

Select the texture, check Read/Write Enabled in the importer, and reimport. Note this doubles that texture's memory — do it only for textures you actually sample on the CPU.

2. Read GPU-only textures via RenderTexture

For screenshots or one-off reads, Graphics.Blit the texture into a temporary RenderTexture, set it active, and use Texture2D.ReadPixels — no import change needed.

3. Watch runtime-created and downloaded textures

Textures from UnityWebRequestTexture are readable only if requested with nonReadable: false; textures you build in code are readable until you call Apply(false, true).

4. Audit before shipping

Search for GetPixels/EncodeToPNG callsites and confirm each target texture's importer — this exception typically ships because the code path only runs on rare player actions.

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 Unity 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.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.