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 iMessage cannot activate on a Mac, the steps you can try yourself, and when it’s time to get professional on‑site help. It applies to:
• iMessage on macOS
• Apple Account activation
• iCloud syncing for Messages
• FaceTime activation issues
If your Mac shows “Activation unsuccessful”, “An error occurred during activation”, or refuses to enable iMessage at all, this page is for you.
The most common reasons iMessage cannot activate on a Mac
These are the issues that Keith Thomas identifies most often during on‑site visits:
• Incorrect Apple Account password
• Two‑factor authentication issues
• Apple Account security blocks
• iCloud Keychain conflicts
• macOS update issues
• Damaged Messages configuration
• Network restrictions
• Corrupted user account
Quick checks you can do yourself
These steps solve around 60% of activation failures.
Check 1 – Restart the Mac
A restart resets iMessage and activation services.
Check 2 – Check your Apple Account password
Most activation failures happen after password changes.
Check 3 – Approve login alerts
Apple often requires approval on another trusted device.
Check 4 – Update macOS
iMessage and activation fixes are often included in macOS updates.
If you see “An error occurred during activation”
This usually means:
• Incorrect password
• Apple Account security block
• Network issue
Try:
• Re‑entering your password
• Approving the login on your iPhone or iPad
• Restarting the Mac
If iMessage activation loops keep returning
This usually means:
• Keychain conflict
• Authentication token expired
• Damaged Messages configuration
Try:
• Removing old Apple Account passwords from Keychain
• Restarting the Mac
• Signing out and back into your Apple Account
If iMessage won’t activate but works on iPhone
This usually means:
• macOS Messages configuration issue
• Keychain corruption
• Damaged user account
Try:
• Signing out and back into your Apple Account
• Restarting the Mac
• Updating macOS
If activation fails after a macOS update
This usually means:
• iMessage services reset
• Keychain reset
• Apple Account re‑authentication required
Try:
• Re‑entering your Apple Account password
• Restarting the Mac
• Updating all apps
If iMessage activates on another user account
This usually means:
• Corrupted user account
• Damaged Messages preferences
• Permissions issues
Try:
• Testing iMessage activation on another user account
• Restarting the Mac
• Reinstalling macOS without erasing data
When DIY stops working
You should get on‑site help if:
• Your Mac refuses to activate iMessage at all
• Activation loops keep returning
• macOS reinstall does not fix the issue
• Messages fail across multiple devices
• You need your data preserved
These issues usually require:
• Apple Account and iMessage configuration repair
• macOS recovery
• Data‑safe macOS reinstall
• User account repair
• Permissions and system file diagnostics
On‑Site Apple Mac Support – London & South East UK
If your Mac cannot activate iMessage, 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:
• Apple Account and iMessage activation issues
• iCloud Drive and Photos syncing
• 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 your Mac cannot activate iMessage, 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