Screenly Forum

Website can´t get displayed


i have a Problem with a couple of multiple Raspberry Pi Devices with Screenly OSE installed.
Two Weeks ago they stopped displaying Websites from IServ which is a Software in the Education Sector.
In IServ there is a Module which provides URLs which then contains specific Timetables/Content for the pupils.

For example this one:

I can access the URL from other PCs without Problems and other Websites work also without Problems with the Screenly PIs.

On the Screenly-Displays there is just a white Screen.

Can anyone help me?