WD Community

Time Machine backup constantly fails

I’ve done everything I can think of and have looked through this and other forums looking for a solution, so I thought I would just post something here and hope that someone has an answer.
I’ve had my PR4100 for a few years and it worked fine for Time Machine backups from my Mac (now on macOS 27) for years. At some point it stopped working consistently for this. I am able to mount the share and usually able to get a few days of backups before I start getting this message:

Once I start getting that message, the backup never completes again. I’ve let it go for 45 days the last time until I decided to turn off Time Machine in the PR4100, delete the share completely and add it back again. I had seen where the “Mobile & Web App Access” should be off, so when I added it back the last time, I made sure that was off. These are my settings:

This all worked again for a few days, but has not worked since yesterday now. The share itself shows that it tried, however (or at least something got updated):

Screenshot 2026-09-28 at 7.22.00 AM

My setup is all wired ethernet. I know I’ve seen some posts about WiFi backup being an issue. I have attempted this with WiFi turned off, so that’s not it either.

One of the main reasons I have the PR4100 is to do TimeMachine backups. I really don’t want to have a local hard drive attached to my machine when I’ve invested so much in this.

Hopefully someone has an answer. Thanks in advance.

Support for Western Digital Hard Drives | Western Digital

Still Need Help?

Reach out to Support for more assistance.

Sign in to Your Support Account

Get up-to-date information about your products.

Western Digital Business Portal

Unlock benefits and tools for your business such as enterprise support, pricing and rebate tools, marketing, loyalty, rewards, and more.