These steps can be tried when Elgato Cam Link 4K video freezes in Elgato 4K Capture Utility, OBS Studio or other software.
Double Check The Port
Ensure that the port the Elgato Cam Link 4K is plugged into is a USB 3.0 port. These ports can often be identified by their blue interior color.
Ensure that the cable being used is the one which came with the capture device.
If a different cable is used, it may not be a USB 3.0 cable and it may cause issues.
Try removing the extension cable that comes with Elgato Cam Link 4K to check if that makes a difference.
USB Controller Drivers
Make sure to install latest drivers provided by your motherboard or notebook manufacturer for the USB 3.x controller. This will ensure that the Elgato Game Capture device is able to connect, and has the best possible performance.
Other controllers usually also work fine with Microsoft's drivers.
Some USB controllers, such as Intel, do not have separate drivers. Instead, these ports use basic Microsoft drivers which cannot be re-installed.
Try All USB 3.0 Ports
Many motherboards have USB 3.0 controllers from different manufacturers, therefore it's worth to try to connect Elgato Cam Link 4K to a different USB port, which is internally connected to a different USB controller.
Other USB ports, such as USB 3.1 and USB 3.2 are backwards compatible and support USB 3.0 devices. Try connecting Elgato Cam Link 4K to those USB ports as well.
There could be bandwidth issues if too many devices are connected to the same internal USB hub or controller. Please make sure the USB hub is USB 3.0 compatible.
Disconnecting other devices or connecting them to different ports can help.
USB ports are controlled by what is called a USB controller. These controllers are used for pairs of USB ports. If both USB ports are occupied by high bandwidth device such as USB capture devices, external hard drives, webcams, etc the available bandwidth may be used up.
Reduce Source Resolution or Frame Rate
Elgato Cam Link 4K sends uncompressed video to the computer. Lowering the incoming source resolution or frame rate directly results in Elgato Cam Link 4K using less USB bandwidth.
Try lowering the source, usually a camera, resolution or frame rate. For example, 1080p60 to 720p60 or 4K30 to 1080p30.
Advanced troubleshooting - For Windows 10 only
Changing the USB transfer mode of the Cam Link 4K can help solve issues. This is an advanced troubleshooting step that can introduce other issues. If you are not comfortable doing this or are unsure if this will help, please contact Elgato customer support.
1) Download and install the Elgato 4K Capture Utility software from http://e.lga.to/download
2) Open the 4K Capture Utility
3) Press and hold down the CTRL key on the keyboard, and then open the settings at the top left of the 4K Capture Utility software
4) In the settings window select the device tab
5) In the device tab, make sure the Cam Link 4K is the selected device
6) Click on the USB Transfer Mode drop down menu and select isochronous
7) Now click on apply and OK. The signal from the Cam Link 4K may disappear for a few seconds, then reappear.
Contact Elgato Customer Support
If all these suggestions have been tried and the Elgato Cam Link 4K video still freezes, please contact our customer support team by going to https://help.elgato.com/hc/requests/new