Unable to find MyCloud PR4100 on the home network

All of a sudden, on my laptop only - no other device is having the same problem - I am unable to find the server within the home network. What do I do to get them talking to each other again. My husband cannot remember how he originally set it up, and does not want to loose any connections to the other devices (x2 desktop PCs).

We are not wanting to go via the cloud, we just want to stay in the home network.

Thanks
Glenys

Also WD Access is not launching

First, see the dedicated subforum for the PR Series where people more knowledgeable with that product may be able to assist. This subforum (My Cloud) generally discusses the single bay/single drive My Cloud which is a different (less capable) device than the PR Series.

https://community.wd.com/c/network-attached-storage/wd-pro-series

Second, if using Microsoft Windows, check to ensure SMB 1.0 is enabled. Microsoft disables this option in later versions (updates) of Microsoft Windows 10.

https://support.wdc.com/knowledgebase/answer.aspx?ID=20736

Also ensure the Network Type is set to Private and not Public in Windows. Finally check any security software installed on the computer. Some may block access to local network devices.