ALM Metrics Not Loaded


Today I get this JS error in web console of an article view causing the metric (ALM plugin) not loading successfully, just endless [ Metrics Loading… ]. How to solve this problem?
I am using OJS and before today ALM plugin always show metrics nicely.

uncaught exception: Invalid JSON:
404 Not Found
Not Found
The requested URL /api/v3/articles/info:doi/10.20884/ was not found on this server.
Apache/2.4.18 (Ubuntu) Server at Port 80