Claude is very good and occasionally very confusing. A paste arrives empty. An upload fails and blames your internet, which is fine. A response stops halfway through a sentence.
Most of these have a specific cause and a specific fix, and most of the advice online is either generic or out of date. These pages are the ones we keep for ourselves, written up properly, and corrected when Anthropic changes something.
The guides
Claude says your pasted text is empty? Five fixes
Paste a long block into Claude and it becomes an attachment, then it says the file is blank. Five fixes, from two seconds to the one that sticks.
Claude file upload not working? Seven fixes
Upload or download failed due to a network issue, error processing file, file too large. Work out which error you have, then fix it, ordered by effort.
Claude stopped mid-sentence? Why, and how to get the rest
Claude cuts off halfway through a sentence and the Continue button does not always help. What is actually happening, and five ways to get the full answer.
Claude network error or "something went wrong"? Fixes for each one
Something went wrong, unknown network error, error 529, service unavailable. Four different faults with four different fixes. Find yours first.
"Authentication service was unavailable. You can try again." What the Claude error means
Getting "Authentication service was unavailable" in Claude? What the error means, why logging back in does not fix it, and how to check.
Claude artifacts not working? Start with the setting everyone misses
The most common cause is one setting in Capabilities. If that is not it, six more causes are covered here, including ad blockers and org sharing settings.
Claude chats disappeared? Where to look before assuming they are gone
Missing conversations are usually still there. Where to check, in order, and how to keep a copy of anything you cannot afford to lose.
Why we write these
We build lead attribution software, which is a long way from browser caches and upload endpoints. But we use Claude every day, we hit these faults ourselves, and the pages we found while looking for answers were mostly wrong. So we wrote better ones.
If a fix on any of these pages has stopped working, or Anthropic has changed something and we have not caught up, tell us and we will update it.
Most of these fixes are about the chat app. If you use Claude Code to build software rather than to chat, the practices that keep an unattended, multi-day build safe are a different set of tools entirely: the control surface behind an autonomous build.
Written by the team at Lead Source, where the day job is working out which marketing actually brings customers.