This error means that you have already reached the limit of the number of products that you can analyze using Seller Assistant extension on the Amazon product pages.
Product lookup limits:
Free Trial period – 750 per month
Start plan – 3,500 per month
Pro plan – 10,000 per month
Business plan – 25,000 per month on monthly plan and 30,000 per month on yearly plan
Business plus plan – unlimited
This limit does not include the analysis of products using the tools in personal account, as well as the analysis of products on Amazon search pages (Quick View) and Storefront pages.
You can view your used limits on the subscription management page in your Seller Assistant account.
Note
If you're sure you haven't reached the limit but the error still appears, please reinstall the Seller Assistant extension in your browser.
You might be interested in the article on How to Change your Plan.