File sharing broken on Mojave

Having a similar issue. I have file-shared between my MacBook Pro & iMac for quite awhile now. Since upgrading the iMac to Mojave, the MacBook Pro can no longer pull up the shared folders on the iMac. The same login/pw remains. I can see the iMac, but get "Connection failed" when I put in the login/pw. Sharing screens and controlling it remotely DOES work. I then tried upgrading the MacBook Pro also to Mojave but it still is not working.

It IS however, working in the other direction. The iMac can pull up the MacBook Pro. I noticed it is logging in with my Apple ID (same on both devices) and tried that from the MBP to iMac, and still got Connection Failed.

Any thoughts on what to tweak are appreciated!

This information from an Apple Rep might help:

for years now Apple has reiterated the deprecation of AFP. And, yes, Mojave is the first macOS that will not boot from an HFS+ volume; it requires APFS. While it is still possible to connect from a Mac with Mojave to a share on a remote HFS+ volume using AFP, you must use SMB to connect to a share on a remote APFS volume. Now that SMB has been the default file sharing protocol for several years now, this should happen automatically. If the connection fails because AFP is still being attempted, prepend "smb://" to your server name, and make sure SMB is enabled on the remote Mac in System Prefs > Sharing > File Sharing. 

So on both my iMac and laptop I made sure SMB was checked in File Sharing options (it was not on the iMac). Now all is working properly.

Yep, exact same here. A new Mac Mini updated to 10.14.5 and sharing became a nightmare. No option to change to AFP sharing as this machine is now running APFS so am forced to use SMB sharing. Connection is extremely unstable and suddenly the three connected users can be dumped and then also experience Finder crashes. This updated has rendered this server so unusable that i've had to wipe it and restore it from a 10.14.4 Time Machine backup. Not exactly ideal in a work environment. Wish i still had my old El Capitan Mac Mini server as it was way better than the Mojave machine i've got now. Hopefully Apple will get on to this soon but i'm not confident having read so many bad reports of Mojave.

I'm having similar issues and it seems to related to the Mojave update. To address some of your consternation-- and based on some info found on other threads-- I believe one of the main culprits is that Mojave turns your main drive into an APFS Volume. According to these threads, the APFS volume is no longer available thru the Apple File Protocol (AFP), only SMB. (To check/change this this, open up Sys Prefs/Sharing/ and view message under File Sharing On.)

It would seem to me if SMB is the ONLY way to share files between computers via the File Sharing option, Apple should provide the steps to make this happen.  The search I conducted on Apple Support resulted in the following instructions which I've found to be somewhat vague <https://support.apple.com/guide/mac-help/set-up-file-sharing-on-mac-mh17131/mac>

I’m starting to wonder if every Mac with 10.14.5 installed suffers from this or if the problem just occurs on some systems. If it is a general bug you would think it gets reported by Mac related news sites und such.

I found another thread here on the forum about it though: https://discussions.apple.com/thread/250388466

It does seem to affect a lot of users and since Erick Mikiten received a hint from Apple support that it is a "known" problem, they seem to be aware of it.

I really hope Apple tries to fix this fast (per "security update" maybe), not put it on a to-do-list for some future 10.14.6 upgrade in a few months or something.

You cannot share APFS volumes over AFP from Mojave. Says so in first paragraph of Set up file sharing on Mac. This is not a sudden Mojave revelation, as Apple has cautioned about this prior to the release of High Sierra.

Thought I would post my HD Formats comparison here between High Sierra and Mojave on an identical iMac hardware config/ setups from two sites:

Mojave is averagely stable, but permissions do not propagate well, but TinkerTOOL Server helped ALOT! :-)

The SHARES themselves do drop off/freeze/disappear either every 2-3 weeks or go mental and require multiple reboots till it settles again.

MOJAVE

HIGH SIERRA

I have this issue as well. I used to (prior to Mojave) be able to use my laptop on my home network to connect to my main iMac in my home office. Now I can't. I get the "Connection Failed" error message. It would be great if someone could address this issue and explain what has changed and why.

Albeer that link to the Apple Support page produces a 404 error. So at the moment, there is no official Apple method for File Sharing functionality the way we used to do it prior to Mojave. I must say I am utterly surprised that Apple engineers either didn't notice this would happen, or haven't addressed this issue. That is a major programming/engineering fail IMHO.

I talked with apple support and seemed to fix it. We had to remove file sharing from the Mojave computer and then add it back on. We also had to update the software on the High Sierra to 10.13.6 and it seemed to connect again. We also had to use the original username and password.. Hope these help...

I have been having this problem since updating to Mojave as well. Like another user, file sharing works from my iMac to my MBP but not the other way around. The File Sharing settings are identical between the two Macs, and both startup disks are APFS.

I did a clean install of 10.14.5 on my iMac that is inaccessible from my MBP, and the MBP is able to connect to the clean iMac (APFS with FileVault enabled).

I also separately did a clean install of 10.14.5 and then migrated my old data from Time Machine, and that install remains inaccessible via File Sharing. So it appears some setting or component from pre-Mojave (or perhaps some other change) is blocking file sharing. Later I will trying just migrating my user and applications (but not system or network settings) to the clean install to see if file sharing remains accessible.

I have been using SMB file sharing between 2 macs, one always the server (file sharing enabled) and one the client (file sharing not enabled) for many years. Updated to 10.14.5 on the client side, everything still worked. Updated to 10.14.5 on the server side and the connection has become flakey, unreliable and eventually hangs. Soon thereafter the server sharing control panel on the server side will not load. Ultimately, the server Mac will not respond to a restart and shutdown from the apple menu: must power down. Both machines are on a wireless network and always have been. The IP address on the server side did change due to DHCP reassignment. I have not found a workaround, but have managed to transfer some data between the server and client before it finally fails.

I have the exact same problem as TMacInc, same usecase. I usually use my iMac as a server that I access from two clients, a Mac mini on El Capitan and a MacBook on HighSierra.

Since I updated my iMac that I use as a server to 10.14.5 I can’t get a stable connection. Sometimes it will work for a while but most of the time not at all. The iMac is always visible in the Finder sidebar or in "Network" but It either doesn’t connect at all or looses connection suddenly. If I try to access again, Finder will sometimes freeze completely, beach ball for several minutes or forever, I had to force shutdown/restart the whole Mac mini several times. I tried switching file sharing on and off or change the settings without any luck. When I try switching file sharing off on the iMac while the clients try to connect it sometimes crashes the whole "Sharing" control panel in a way I can’t even shut it down and have to restart the Mac.

I had no problems with previous instances of Mojave, only since 10.14.5. From the 10.14.5 iMac I can access the other Macs perfectly but that’s not how I usually want to use it.

This is a major issue but from previous experiences I can only hope that another Mojave update will fix it at some point (I’ve had different problems with lost network connections in two or three OS X versions before and with another system update they were suddenly gone so I’m not very confident I can fix it myself in any way).

Same thing here. Four person office and seems that shortly after an automatic update to 10.4.5, our Mac mini file sharing "server" started dropping all four clients. Maybe spontaneously, maybe at high traffic moments - hard to say.

It seems like a network or hardware problem, so we replaced our router, switch, and several Ethernet cables after trying many other network setting changes and several power cycles of the LAN. We got on for half a day then were bumped off.

Got a new server machine (13" MBP) thinking that it was a hardware problem with my MacMini. Set up the MBP from a Carbon Copy Cloner backup and worked for a day then the problem came up again.

Seeming NOT to be a hardware issue on the Mini, we wiped and set up the Mini again as a "brand new" Mac. This at the suggestion of the third or fourth Apple support person (senior) I spoke to. This worked for about 12 hours and broke again.

Finally after 8 days of my office being mostly dead in the water another Apple rep tells me about the "known" SMB problem with 10.4.5, and that I should roll back to the previous OS. Doing that now from a Time Machine backup that caught the previous version over a week ago. Then have to figure out all the files that the four of us changed since then.

I don't know if I'm more upset that this has been an issue for so many users for so long, or that I went through so many senior support people troubleshooting this network problem before one finally pointed this out. I just hope this messy restore process will solve the problem.