Chrome extension warns "Cannot load extension with file or directory name Thumbs.db. The filename is illegal."

Question

Whenever I use "load unpacked" to test my custom Chrome extension, I get an error:

There were warnings when trying to install this extension:

• Cannot load extension with file or directory name Thumbs.db. The filename is illegal.

I am testing my extension by:

• Opening Chrome's extensions page (chrome://extensions)
• Ensuring "Developer mode" is enabled in the top-right corner
• Clicking "Load unpacked" and selecting my extension folder.

I don't see Thumbs.db in my extension folder, so I'm not sure what the warning is for.

Answer 1

Open Windows 'Folder Options' and select the 'View' tab. Under 'Advanced Settings', select 'Show hidden files, folders, and drives' then select 'OK'.

Doing this will show the Thumbs.db file inside the folder where you are keeping pictures/icons relevant to your extension. Delete it.

To prevent creation of Thumbs.db again, I reckon, setting the folder type to 'General Items' should do the trick.

Answer 2

To fix this enter the path:

Control Panel\All Control Panel Items\File Explorer Options

Click

View

In "advanced setting" Uncheck

Hide protected operating system files (Recommended)

And apply

---

To Prevent this from occurring make sure in

Properties (Customize)

of that folder that

Optimize this folder for:

is

"General Items"