Connection denied by IP2Location Country Blocker

Some time ago, I installed the IP2Location Country Blocker plugin because the site was getting flooded with spam visits from countries in Eastern Europe, Africa, etc. in this site:

However, the client informed me that they cannot view the site, as the following message appears:

“Connection denied by IP2Location Country Blocker Please contact web administrator for assistance.”

I tried installing a caching plugin (WP Fastest Cache) since that should have resolved the issue, but the problem persists…

I cleared the browser cache, but the problem persists…

I would appreciate any help on this matter.

Thank you very much and best regards!