If the WebModel is hosted on a web server (address in the browser starts with http[s]://) and the linked files are still saved on a file server (address starts with file://), it is possible that the linked files on the file server cannot be accessed via the WebModel.
This is caused by a zone change to be performed by the browser (web server = Internet/Intranet zone; file server = Intranet/local computer).
Since most browsers classify the change from a more open zone (Internet) to a more closed zone (Intranet) as a security risk, the browser blocks the change.
We have got no access to these browser restrictions and can therefore only show you two workarounds or recommendations.
Option 1:
When exporting the WebModel, you select the option "Copy linked files to the target folder" (see screenshot). This ensures that all linked files are copied to a folder in the WebModel directory and that the files are then also located on the web server.
The only disadvantage of this procedure is that when you update a file copied in this way, you must perform a new WebModel export to make the new version available in the WebModel for all users.
Option 2:
The documents are also stored on a web server (in the same zone), for example in a document management system (DMS) or Microsoft Sharepoint. The link is linked once in viflow and the maintenance of the data takes place via the corresponding system.