The cause:

The string you gave cannot be converted into an image by docker. When you execute the image using the docker run command line, this could be an invalid name or the result of a parsing issue earlier in the command line. Or in the case you use all capital letters in the name of your register or repository. When using the docker run command line, this frequently happens as a result of failing to quote parameters with spaces, forgetting the value of an argument, and misreading the command line’s order. Another reason is that a volume mapping is expanding a route name with a space in it when delivering arguments to the run and neither quoting the path or escaping the space. These are the reasons of your error.

Solution:

If you try to run Project:latest with the command Dir:/data image_ref while in the directory /home/user/Some Project Dir, that will define an anonymous volume /home/user/Some in your container. And here’s how to solve that, let’s use:

docker run -v "$(pwd):/data" image_ref

If the environment variables are missed:

docker run -e SOME_VAR=Value With Spaces image_ref

Which docker will consider this as attempting to execute the command Spaces image_ref while using the image With:latest. The solution is using the environment parameter:

docker run -e "SOME_VAR=Value With Spaces" image_ref

In case you have:

version: 2
services:
app:
image: ${your_image_name}

Let’s check carefully whether that your_image_name is declared as an all-lower case string or not.