The request for resources/list can be very time consuming and can take upto 30 seconds in worst cases (depending on the performance of the network, StoreFront server or other components). This can cause timeout on the Receiver UI. But the response has been received successfully on the Receiver side.
Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.
We can figure out whether this issue is caused by network latency by adding the following registry key on the client:
WebUILoadingWatchDogTimeoutMs controls the timeout value of watchdog.
Alternately, turn off the Unified Experience in StoreFront (if Receiver 4.4 is being used).