Sometimes, while you're happily using Ahrefs, this "warning" pops up:
This pop-up (and various other similar pop-ups) tells you that you've hit certain limits in your subscription plan.
In order to continue using Ahrefs (or 'break' the limit), you'll have to upgrade your Ahrefs plan or wait for the monthly renewal on the stipulated date (the date above is an example; your date may vary)
Here's how you can check everything related to your subscription limits:
Go to "Limits & usage" report under Workspace in your Account settings:
From there, you will be able to check:
When your limits (monthly & weekly) reset;
When your next billing date is;
How much more you have to go w.r.t the different tools in Ahrefs (e.g Site Explorer, Rank Tracker, etc.).