This could happened for few reasons:
⇒ The dot pixels don't reach the minimum light threshold: (~ 10%)
→ Check if the projector brightness is high enough.
→ Check if you can increase the camera sensibility.
⇒ The ambient light is too high:
→ Keep ambient light as low as possible.
⇒ The camera resolution is too small:
→ The min. resolution is 1080px, but 2048px or more is recommended.
⇒ Be sure that most dots are visible from the camera.
  Note: You can see the last calibration pictures in the MyDocuments/NestMap/CalibPic folder. NestMap places a + where dots are detected and this could help to diagnose calibration problems.
If you have dots over an object that is not part of the screen, you can disable those dots by:
1. Activating the camera view, this will showup all dots.
2. With the mouse, navigate through projector's screens and click on the dots you want to hide (they should turn red).
3. Disable the camera preview and start a new calibration. NestMap will interpolate the missing dots.
Green dots are important and cannot be hidden.
If you get correct blend with pure white, red green and blue, but not with Dark Orange, Sky Blue or Purple, this is mostly caused by the projectors color mode. Try to change parameters in projector. For example, try the "cinema" mode, disable Eco or dynamic brightness, white temperature, etc…
Sometime it's just impossible to have a perfect blend for all colors with some projectors. In this case, adjust the blend with a bright still frame of your main movie to get best results.
This could happen for one or many of these reasons:
⇒ Some display drivers use the "limited color space" by default, which restrain RGB values between 16-235:
→ Change the color space to "Full 0-255" could help.
⇒ Some projector technologies have higher black levels than others:
→ Try to fix it by changing projector settings, but maybe consider another kind of projector.
⇒ In NestMap V1.0.0.6 and above, you can use the "Black level adjust" slider if all other solutions are not enough.
NestMap can only use Spout surface compatible with DirectX9. If you have this message, this means that the Spout sender uses a DirectX11 surface with a color space that is not retro compatible with DirectX9.
Try to use the color format DXGI_FORMAT_B8G8R8A8_UNORM. If your project is in Unity, you could use this edited KlakSpout unitypackage who is already in this color format.
This message is popup by the Spout library and mostly occurs when the Spout surface is created on another GPU than where the main monitor is connected. If you have more than one GPU, please declare one of the device connected to the GPU you are using for the Spout sender as the "main monitor" in Windows settings.