For others, https://chrome.google.com/webstore/detail/docsumo-free-ocr-software/ihmmlfacoffajllfpdfkdikgmoogbnph/ seems to be the extension.
When clicking "Capture selected area" or "Capture visible area" in the Extensions icon popup menu, I get an error in the console that says:
Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.I get the error in Chrome and Brave too. I think the extension is just broken or whatever site/server it relies on doesn't exist anymore. There's a support section on the extension's page in the Chrome webstore. You could report it.
Reloading the page like the extension says to do doesn't help.