After updating to the Catalina 10.15 Beta (19A487l), I am no longer able to connect to my network drive via SMB. I get the following error:

There was a problem connecting to the server "ServerName". The server may not exist or it is unavailable at this time. Check the server name or IP address, check your network connection, and then try again.

However, I am still able to connect to the network drive from a Windows 10 machine and a macOS Mojave machine.

Is anyone else having this issue? Is it an issue with Catalina or is there something else I can do to try to resolve this?

  • What build is your os? Please edit that into your question body. If you want to share the OSR version of a 70 on the server-side that would be good too. Due to the NDA, you may not get many answers here, but it is on topic. – bmike Jun 20 at 0:30
  • @bmike Thank you for the feedback. I'm new here. I didn't even think of NDA's. Thank you for the insight! – SonBrooks Jun 20 at 0:32
  • No worries - we love questions and Ask Different Meta has all sorts of things. Often troubleshooting from old OS can answer beta questions. Also, if someone says “check the known issues” or can point to the developer discussions that are open - sometimes great answers here happen without people breaking any agreements to not show screenshots or whatever the language this year is for pre-release software. Worst case it languishes until you figure it out or release date and an official answer can be placed. – bmike Jun 20 at 0:33

The solution is in Catalina release note


NetBIOS is disabled in macOS 10.15 to speed up mounting, browsing, and connecting to SMB shares. Some older printers and file servers may require NetBIOS to connect. (51119111)

To enable NetBIOS, you can create or edit the /etc/nsmb.conf file. If your system doesn't already have an /etc/nsmb.conf file, use the following Terminal commands while logged in as an Administrator:

echo "[default]" | sudo tee -a /etc/nsmb.conf
echo "port445=both" | sudo tee -a /etc/nsmb.conf

To disable NetBIOS, you can safely delete the /etc/nsmb.conf file.


I have the same issue after updating to macOS Catalina Version 10.15 Beta (19A487m)

I have a network drive connected to a router using SMB:// Its a 8TB readyshare.

This has always connected automatically and is primarily used as a backup. Since the update this has been unavailable and if I try to connect I get the same error as above.

If I try to browse it shows the drive but will not connect. This is shared with a Windows 10 machine and another Mac that can both connect as normal.

I did wonder if it was the way the drive was formatted that was causing the issue.

Any help would be appreciated.

  • Welcome to Ask Different :) The place is reserved for posting the answer to the original question. However, this post does not actually answer the question. If you have one, please consider editing your post and share it. If you have a separate question, ask it here. Else, consider deleting this post. – Nimesh Neema Jul 1 at 17:41

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