Several JSON Schemas mapped to this file: system scheme 'schema.json'; system schema 'packageJsonSchema.json'

Hi - 

I'm getting the following warning message on my package.json file, but haven't been able to work out how to resolve this. 

Several JSON Schemas mapped to this file: system scheme 'schema.json'; system schema 'packageJsonSchema.json'

When I click on the 'Edit JSON Schema Mappings'. link next to the warning message a new dialogue box opens up asking me to add a JSON schema file and configure its usage. The dialogue box is blank, with no sign of the two schemas mentioned in the warning message. When I add in a schema as per this https://youtrack.jetbrains.com/issue/WEB-22082 the new schema will be listed in the error message along with the other two already mentioned above, but the error message still continues and I can't track down the other two schemas. 

Another issue (which I mention as it's perhaps related) is that in my .js file there are a few references to JSON values have a warning 'Unresolved Variable'.

Any help much appreciated.

Disclaimer: I'm very new to WebStorm and still trying to get the hang of the overall set up. 

Many thanks