Quota error message when making an API call

Has anyone seen a situation where they make a call to the API and get a message like this back even though they have plenty of quota available in their account?

ERROR WHILE FETCHING THE ANSWERS %s You exceeded your current quota, please check your plan and billing details. For more information on this error,

So basically our API calls are failing because it thinks we don’t have available quota when we actually do.
Note: We are on a Tier 4 plan with plenty of quota remaining for this month.

i was facing same issue for my API call and after searching here and there find an issue . you can visit this link https://platform.openai.com/account/billing/overview and see if Credit balance
is not in minus. after recharging it again start working but i have generated new API key after recharching

A vast swath of people actually. Monthly billing accounts are being bumped off of that plan by OpenAI and into requiring a pre-paid credit. This transition immediately interrupts service if you haven’t purchased credits to be added to your account.

Many emails should be received in the lead-up to the switch, but some developers have reported getting no correspondence.

Turns out of credit balance was negative. How long after we add credits does the API start allowing requests again?