Steps to Reproduce:

1. go to page: https://vamos.apinf.io and login as an API owner
2. Click an API and go to documentation tab
3. Click Manage button, select File type from dropmenu and click choose file.
4. 1st try to select a non json/yaml/yml file
5. Observe the s-alert about file format.
6. now upload a json/yaml file and click save

Outcome:
No preview appears behind the API documentation dialog
Uploaded json/yaml/yml API documentation doesn't get loaded in the documentation tab. Spinner keeps on loading.
spinner appears above if API document dialog is opened via Manage button.
http://recordit.co/Nnpbq1v31F

Expected Behavior:

It should be possible to load a valid json/yaml/yml file after the previous attempt to upload a non-supported file format.
Documentation should appear normally in the documentation tab

Environment:
Windows 10, Chrome browser (latest), APInf vamos deployment (https://vamos.apinf.io)