Clicking it should open a popup with the following text:
Typical explanations for "Block not found" error.
Are you trying a transaction hash from the latest block on Etherscan? Sometimes the Alchemy nodes we use are a bit behind and don't have the latest blocks. Wait a minute and retry or try an older hash (if you just want to see how the tool works)
You've selected a different network that the one transaction was executed on. Please double check.
If neither of these explanations apply to your case kindly follow a link to report a bug.
Clicking it should open a popup with the following text:
Typical explanations for "Block not found" error.
If neither of these explanations apply to your case kindly follow a link to report a bug.