You need to render at least 2 passes to use the denoiser.

You need to render at least 2 passes to use the denoiser.

This warning appears if the denoising option was enabled, however not enough passes were rendered for it to work. Denoiser needs at least 2 passes to work.

Possible causes:

• Rendering was stopped too early by the user
• Rendering was stopped too early by the time/pass/noise limit

Solutions: 

• Wait until at least 2 passes are rendered
• Increase or disable the progressive rendering limits
• Use the "resume rendering" option to render more passes