ChatGPT Claude Gemini API Key Troubleshooting Checklist: Get Your Requests Back to Normal Immediately

The most frustrating thing isn’t that the model isn’t smart enough—it’s that right after you finish writing a piece of calling code, it hits you with Invalid API Key, 403, or “Network connection failed.” I’ve organized the pitfalls I’ve personally run into into a universal troubleshooting checklist for ChatGPT OpenAI, Claude Anthropic, and Gemini, and I’ll also briefly mention common permission issues with Midjourney.

Three types of issues you can fix at a glance

The key is entered wrong or placed in an old project

A lot of people accidentally paste extra spaces before or after the key, or drop a test-environment key into production. I suggest copying the key into plain text to take a quick look, then pasting it back.

The request is sent to the wrong endpoint or model name

A wrong model name can also make you think the key is wrong. Don’t brute-force it—follow the “keep it simple” mindset (the KISS principle really works): first get the most basic official example request working, then add parameters.

Environment dependencies drag you down

If you’re using an off-the-shelf plugin or scaffold (for example, dependency conflicts common in some Node plugins like ETARGET or ERESOLVE), install dependencies cleanly and align versions first—otherwise you’ll waste an hour on a “key error” that isn’t actually a key issue.

How to handle 403 access restrictions and network issues

If you run into 403, regional restrictions, or prompts like “Network connection troubleshooting,” check your corporate proxy, gateway, and cloud server outbound routes first. Often it’s not that the model is rejecting you—your network is messing up TLS or DNS resolution.

Midjourney doesn’t use an API, but it has similar failure points

Midjourney is mainly used in Discord, and the common issues are instead: you’re not in the right server, you don’t have enough channel permissions, or your subscription has expired so commands don’t respond. Don’t keep editing code locally—check Discord permissions and subscription status first.

My go-to quick isolation order

• Use a minimal request to verify whether you can get a response
• Try a different network or disable your corporate proxy once
• Regenerate the key and replace the environment variable immediately
• Confirm the model name, API domain, and regional configuration are consistent

If you’re still stuck on “blocked at the door” issues like topping up, subscriptions, or regional access, consider checking out Titikey for a more hassle-free solution. I’ve compared options myself—having to tinker less is genuinely worth it.