Debog Log Analyser is a client side application which runs on browser and accesses log information from the Salesforce Org using REST API. To successfully recieve a response from the Salesforce server kindly add the domain of this application to the Salesforce Org's CORS whitelist.

For more information, refer this article.

Please follow below steps to whitelist the domain in target Org.

1. From Setup, enter CORS in the Quick Find box, then select CORS.
2. Select New.
3. Enter the Origin URL Pattern as https://dla.isoftspot.com
4. Retry logging in to Debug Log Analyser.