I'd recommend to push everything to tableau server as a packaged workbook.
File Type .twbx
This will ensure that all the images load successfully.
Pls don't use URL actions, as it will point to another URL, rather use dashboard actions to load images.
Trust me i've done this successfully as shown here:
Click on the second tab & see how the images change.
I understand, but we are talking about 1100 images, almost 1 GB in size, and they change every few days (new hires and resignations), so is not an option a controlled group of images. I would have to keep re-publishing the workbook, and that is an administrative nightmare.
URL actions should work, I just need to figure out this error.
This is a local server, BTW, nothing that can be exploited from the internet. Is way under the firewall, and users should connect to a VPN before they can access it remotely.
Fixed it moving the files to an FTP server. Accessing a local file apparently is not recognized as a url protocol.