Linking music Folder to Sonos

I store my music in a share on a WD Ultra 2 and this has been used by my Sonos fine. Now I can not link the share to the Sonos, I get the following message

I have tried using the NAS user and pw, and no pw but same result, is there something in the NAS settings that has changed?

I have created a new share but same results, but I am able to link a share from a WD My Cloud NAS

Cheers

If you haven’t already you may want to see the dedicated OS5 EX Series subforum where there is much EX2 Ultra discussion. There are several discussions in that subforum discussing specific SONOS issues with OS5.

https://community.wd.com/search?q=Sonos%20category%3A255

Some examples, perhaps there may be a answer in them:
https://community.wd.com/t/after-update-to-os-v5-not-working/258033
https://community.wd.com/t/ultra-ex2-os-5-twonky-server-sonos-issues/260500
https://community.wd.com/t/no-access-to-the-nas-after-upgrading-to-os-5-even-after-resets/258337

Many thanks, read and changed setting to SMB1, all working fine>