To add to this, if you are seeing HTTP turn into HTTPS, it looks like either your browser or your server where the webclient is installed has an HTTPS redirect turned on.

HTTPS redirect can be set in IIS for all people accessing the site, or can be done in the browser on just your computer.

Since you do not have a certificate in IIS and you are getting redirected to the HTTPS version of the site, it will fail.

We strongly recommend always setting up HTTPS, and it seems like that's a default for you as well, since the HTTPS redirect is happening. As such, I recommend setting up an IIS certificate for HTTPS as a first troubleshooting step.

Beyond that, as Miruna noted, this is not a Laserfiche-specific error, so if that does not resolve the issue, I would look into IT policies, try other browsers, etc. to pinpoint the issue.