error converting YAML to JSON: yaml: line 16: found a tab character that violates indentation

We might be got this error when executing kubectl command:

$ kubectl apply -f test1.yaml 
error: error parsing test1.yaml: error converting YAML to JSON: yaml: line 16: found a tab character that violates indentation

Fix it: Use vim to open this file, then :set list, then you will see the special characters.