failed to solve with frontend dockerfile.v0: failed to create LLB definition: dockerfile parse error line 21: unknown instruction: VN

It seems that there is an error in your Dockerfile syntax. The error message indicates that there is an unknown instruction "VN" on line 21.

Without seeing the full Dockerfile, it's difficult to pinpoint the exact issue. However, it's possible that you have a typo and meant to use the "ENV" instruction instead.

Here's an example of the correct syntax for setting an environment variable in a Dockerfile:

FROM some-image
ENV MY_VAR=my_value

Make sure to review your Dockerfile and check for any typos or syntax errors. Once you've made the necessary changes, try building your Docker image again.