While setting userTags in the install-config file for AWS does not support all AWS valid characters as per [1].  
platform:
  aws:
    region: us-east-1
    propagateUserTags: true
    userTags:
      key1: "Test Space" 
      key2: value2

ERROR failed to fetch Metadata: failed to load asset "Install Config": failed to create install config: invalid "install-config.yaml" file: platform.aws.userTags[key1]: Invalid value: "Test Space": value contains invalid characters

The documentation at: https://docs.openshift.com/container-platform/4.16/installing/installing_aws/installation-config-parameters-aws.html#installation-configuration-parameters-optional-aws_installation-config-parameters-aws does not refer to any restrictions.

However:

Validation is done here:

https://github.com/openshift/installer/blob/74ee94f2a34555a41107a5a7da627ab5de0c7373/pkg/types/aws/validation/platform.go#L106

Which in turn refers to a regex here:

https://github.com/openshift/installer/blob/74ee94f2a34555a41107a5a7da627ab5de0c7373/pkg/types/aws/validation/platform.go#L17

Which allows these characters: `^[0-9A-Za-z_.:/=+-@]*$`

[1] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#tag-restrictions).

    100 %

    1. Create a install-config with a value usertags as mention in description.
    2. Run the installer.


   
    

Command failed with below error:

ERROR failed to fetch Metadata: failed to load asset "Install Config": failed to create install config: invalid "install-config.yaml" file: platform.aws.userTags[key1]: Invalid value: "Test Space": value contains invalid characters

    Installer should run successfully.

    In userTags when the value with space is set then the installer failed to compile the install-config.