Why Choose Keith Thomas
• 20 years of experience as a Senior Apple Support Specialist at Apple Computer UK HQ.
• Former Apple Computer UK Mac Support Specialist and Apple Authorised Service Provider background.
• Established and Independent since 2010 for on‑site Apple Support Service – no call centres, no outsourcing, no hardware repairs. Over 25,000+ Apple problems resolved. Unique on-site Apple Support Service. backed up with Independent Apple Telephone Support Assistance.
• Trusted by home users, small businesses, and professionals across London and the South East UK.• Clear, honest, software‑only support. No Hardware Repairs. Expert Apple Consultancy Service.
On‑site Apple Mac Support in London and the South East UK
What this page covers
This guide explains the real reasons Microsoft 365 is not working properly on a Mac, the steps you can try yourself, and when it’s time to get professional on‑site help. It applies to:
• Microsoft 365 on macOS
• Word, Excel and PowerPoint
• Outlook for Microsoft 365
• OneDrive for Mac
• Microsoft Teams for Mac
If Microsoft 365 apps will not open, keep crashing, refuse to activate, will not update, or will not sync files, this page is for you.
The most common reasons Microsoft 365 is not working on a Mac
These are the issues that Keith Thomas identifies most often during on‑site visits:
• Out‑of‑date Microsoft 365 apps
• macOS compatibility issues
• Microsoft 365 activation problems
• Microsoft 365 account login issues
• Corrupted Microsoft 365 installation
• Damaged user profile or preferences
• OneDrive sync problems
• Network and firewall restrictions
Quick checks you can do yourself
These steps solve a large number of Microsoft 365 problems on a Mac.
Check 1 – Restart the Mac
A restart resets Microsoft 365 services, network connections and background processes.
Check 2 – Check for Microsoft 365 updates
Open Microsoft AutoUpdate and install all available updates for Word, Excel, PowerPoint, Outlook, OneDrive and Teams.
Check 3 – Check your Microsoft 365 subscription
Sign in to your Microsoft 365 account in a web browser and confirm your subscription is active.
Check 4 – Update macOS
Microsoft 365 often relies on the latest macOS updates for compatibility and security fixes.
If Microsoft 365 apps will not open
This usually means:
• Corrupted Microsoft 365 installation
• Damaged app preferences
• macOS permissions issues
Try:
• Restarting the Mac
• Updating Microsoft 365 apps
• Removing and reinstalling Microsoft 365
If Word, Excel or PowerPoint keep crashing
This usually means:
• Out‑of‑date Microsoft 365 apps
• Damaged templates or add‑ins
• Corrupted user profile
Try:
• Updating Microsoft 365 apps
• Restarting the Mac
• Testing in a new macOS user account
If Outlook for Microsoft 365 is not working
This usually means:
• Damaged Outlook profile
• Email account authentication issues
• Microsoft 365 account problems
Try:
• Updating Outlook and Microsoft 365
• Restarting the Mac
• Rebuilding the Outlook profile
If OneDrive is not syncing on your Mac
This usually means:
• OneDrive not signed in
• Out‑of‑date OneDrive app
• File path or permissions issues
Try:
• Signing out and back into OneDrive
• Updating the OneDrive app
• Restarting the Mac
If Microsoft Teams is not working on your Mac
This usually means:
• Out‑of‑date Teams app
• Microphone or camera permissions issues
• Network or firewall restrictions
Try:
• Updating Microsoft Teams
• Checking macOS privacy settings for camera and microphone
• Restarting the Mac
If Microsoft 365 will not activate on your Mac
This usually means:
• Microsoft 365 subscription issue
• Wrong account signed in
• Activation service problem
Try:
• Signing out of all Microsoft 365 apps
• Signing back in with the correct Microsoft 365 account
• Checking your subscription status online
If Microsoft 365 stopped working after a macOS update
This usually means:
• Compatibility changes
• Microsoft 365 apps out of date
• Permissions or security changes
Try:
• Updating all Microsoft 365 apps
• Restarting the Mac
• Checking macOS security and privacy settings
If Microsoft 365 works on another user account
This usually means:
• Corrupted user account
• Damaged Microsoft 365 preferences
• Permissions issues
Try:
• Testing Microsoft 365 in another macOS user account
• Restarting the Mac
• Reinstalling macOS without erasing data
When DIY stops working
You should get on‑site help if:
• Microsoft 365 apps will not open at all
• Word, Excel, PowerPoint or Outlook keep crashing
• OneDrive refuses to sync your files
• Microsoft 365 will not activate on your Mac
• Microsoft 365 stopped working after a macOS update
• You need your data and documents preserved
These issues usually require:
• Microsoft 365 and macOS configuration repair
• Microsoft 365 profile and preference repair
• macOS recovery
• Data‑safe macOS reinstall
• User account and permissions diagnostics
On‑Site Apple Mac Support – London & South East UK
If Microsoft 365 is not working on your Mac, Keith Thomas provides an often same‑day on‑site support service across:
• Central London
• West, North, South and East London
• Surrey
• Berkshire
• Hampshire
• Wiltshire
Keith Thomas is a Mac Support Specialist in:
• Microsoft 365 and Outlook problems on Mac
• OneDrive and file syncing issues
• macOS configuration repair
• Data‑safe macOS recovery
• macOS reinstall and repair
• New Mac setup and migration
• User account and permissions diagnostics
Book on‑site help in London and the South East UK
If Microsoft 365 is not working on your Mac, Keith Thomas can visit your home or office and get you working again.
Keith Thomas – Apple Mac Support Specialist
Established 2010 – Open 09:30–20:30, 7 Days
Contact Keith Thomas by Telephone: 07800 940756 or by Text to: 07800 940756, or simply complete an online website contact form 24/7