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 Mac apps won’t open, the steps you can try yourself, and when it’s time to get professional on‑site help. It applies to:
• MacBook Air
• MacBook Pro
• iMac
• Mac mini
• Mac Studio
If apps bounce in the Dock, crash immediately, or refuse to launch, this page is for you.
The most common reasons Mac apps won’t open
These are the issues that Keith Thomas identifies most often during on‑site visits:
• Outdated apps
• Damaged app files
• macOS update issues
• iCloud or Apple ID syncing conflicts
• Insufficient disk space
• Damaged system files
• App permissions issues
• Corrupted user account
Quick checks you can do yourself
These steps solve around 50% of app‑launch issues.
Check 1 – Restart the Mac
A restart clears temporary processes and resets app services.
Check 2 – Update the app
Open the App Store → Updates, or update directly from the developer.
Check 3 – Update macOS
System Settings → General → Software Update.
Check 4 – Check free disk space
Go to Apple menu → About This Mac → Storage. Aim for at least 20GB free.
If an app bounces in the Dock but won’t open
This usually means:
• Damaged app files
• Missing permissions
• macOS corruption
Try:
• Updating the app
• Restarting the Mac
• Reinstalling the app
If an app crashes immediately
This usually means:
• Outdated app version
• macOS update conflicts
• Damaged system files
Try:
• Updating the app
• Restarting the Mac
• Booting into Safe Mode
If apps won’t open after a macOS update
This usually means:
• App incompatibility
• Spotlight indexing
• iCloud syncing delays
Try:
• Leaving the Mac plugged in for a few hours
• Restarting the Mac
• Updating the app
If apps won’t open on a specific user account
This usually means:
• Corrupted user account
• Damaged preferences
• Permissions issues
Try:
• Testing the app on another user account
• Restarting the Mac
• Reinstalling macOS without erasing data
When DIY stops working
You should get on‑site help if:
• Apps refuse to open repeatedly
• Apps crash immediately every time
• macOS reinstall does not fix the issue
• Disk Utility shows errors
• You need your data preserved
These issues usually require:
• App and system 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 apps are not opening, 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:
• App launch and crashing issues
• macOS configuration repair
• Data‑safe macOS recovery
• macOS reinstall and repair
• iCloud and Apple Account issues
• New Mac setup and migration
• User account and permissions diagnostics
Book on‑site help in London and the South East UK
If your Mac apps are not opening, 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