This is a notable pending problem. Not because of EOL but because no later reliable Office version for saving to SMB sharepoints via macOS Clients.
Office 16.78 is under the Office 2019 umbrella.
Microsoft Office version is clearly or consistently better and more reliable than 16.78 for saving directly to SMB/network file servers, based on extensive searches across Microsoft forums, sysadmin communities (Reddit r/macsysadmin, Synology forums), and tech discussions up to June 2026.
16.78 (and nearby builds in the 16.6x–16.78 range) was often in a relatively stable window for many SMB-heavy users. Earlier updates (e.g., around 16.63.1/16.64 in 2022) introduced regressions, such as save failures on Synology SMB shares involving temporary file errors or folder names with square brackets []. Users explicitly noted that “Excel and Word were the most reliable products for saving to my Synology SMB shares” before those changes.
Newer versions (post-16.78) — including current Microsoft 365 builds (around 16.110 as of mid-2026), Office 2021, and Office 2024 for Mac — do not have widespread reports of superior SMB reliability. Issues persist or evolve:Saving/locking problems on Windows Server shares and NAS devices (Synology, etc.). Interactions with macOS SMB client changes (especially Sequoia and later). Temporary file/folder creation glitches during saves. Inconsistent behavior with concurrent access or specific path/folder naming.
Microsoft’s own position (from support responses): Direct saving to SMB/CIFS locations “is not directly supported” in Office for Mac. It may work in practice but is not guaranteed. They strongly prefer OneDrive or SharePoint for the best experience.
No version in the 16.8x, 16.9x, or 16.10x range (or Office 2024 perpetual) stands out in discussions as a clear upgrade for pure SMB workflows. Some users report similar or new quirks after updating, often tied more to macOS version or server configuration than the specific Office build.
SMB discussion
