The error detail is:
Just as the following picture shows:
2.1 How to trigger this error?
cmd+shift+p: then choose pretty json,just as following picture shows:
then you can see this error:
2.2 Some reasons of the error
probable reason #1:
probable reason #2:
I found that if I click on the OK button on the alert dialog box and then close all the open tabs in Sublime Text 3 and then close ST3 and reopen it, the error message no longer comes up.
2.3 My solution
Just close the json files and all other tabs in sublime text.
Then exit sublime text process.
And open sublime again, open the json file and save it as xxx.json.
Finally , test the json format again, it works!