Problems with file sharing with Mojave 10.14.5

I’ve been unable to connect to my iMac running Mojave with my MacBook Pro, which is still on High Sierra, and I’m not the only one. It looks like it is not just a case of switching smb on, which was suggested in one Apple discussion thread:

https://discussions.apple.com/thread/8616638

I already had smb switched on on both machines, and switching off afp did not solve the problem. It turns out that it also affects machines that both run Mojave:

https://discussions.apple.com/thread/250388466

This apparently started with the latest Mojave update (10.14.5), which I also installed. File sharing works OK the other way around (starting the connexion from the iMac), but I synchronize folders between the two machines from my MacBook, so a connexion from the iMac is not a solution.
My workflow is quite hampered at the moment. Could some attention in TidBITS spur Apple to fix this problem soon?

I’ll look into it more. Thanks for the heads-up!

My understanding is that SMB has been the default for macOS file sharing since 10.9 Mavericks. But that doesn’t seem like it would be related here.

This happened to me once about 5 months ago (MacPro in High Sierra, sharing a couple of disks with 2 iMacs in High Sierra, and one laptop in Mojave, suddenly the Mojave laptop would not connect to the MacPro), and besides the SMB switch mentioned, I also changed the name of the server, turned off File Sharing and back on again, and rebooted all the machines. Luckily that fixed the problem for me, and (knock on wood), haven’t had issues since.

However, I am keen to know if there are other solutions or additional advice just in case as it was not fun (always seems to occur when deadlines approach, and not randomly on sleepy Tuesday afternoons).

Seconded. I recall having a smilar issue between an EC and a HS Mac. Like @seth I was eventually able to get around it by stopping/starting file sharing and rebooting, but it would be nice to know what the actual error is and how to fix it without resorting to Windows-esque voodoo methods. :wink: