Local Lan Links failed on some clients

Hi. Im running the 2014 theme on V4.4.2 using IE11.

I don’t think its a browser issue because I have exactly the same version on a working client. I have cleared my cache, logged out/in and tried again. ??

I have an Intranet that’s been working fine but today two clients have stopped processing links to folders/files on my lan.

Everything else is hunky dory. The links have been working for a long time (months) but just suddenly are zero responsive.

I click on the link and absolutely nothing happens. I can still access the folders/files via windows explorer as normal, so the connectivity is fine.

When I hover over a link it shows the relevant path, for example file:///O:/ which links to a mapped network drive.

I hope this is a simple fix. Over to you Guys n Girls.
Crosses fingers and adopts a praying position.
Thanks in advance.

Gaz.