What is your anti-virus software?

Hi christ1

Thanks for responding to my question

I'm using Avast 12.3.2280

See https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues#AVAST

Thanks christ1 for the link

None of the Avast sections matched my circumstances (as far as I can see)

I note from the beginning of the document that the definitive test is to start in safe mode. I have done that and Thunderbird still is "not responding"

Further suggestions please

Try to start Windows in safe mode with networking enabled. - Win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

Still in Windows safe mode, start Thunderbird in safe mode. - https://support.mozilla.org/kb/safe-mode

Does the problem go away?

Following the instructions the problem does not go away

But if I select "disable add-on" in TB safemode box and continue then TB Lightning add-on is disabled by safe mode and TB works for emails

If I close TB and try to run TB in normal mode whilst win 10 is still in safemode get the "not responding" message

Further help please

Please post your Troubleshooting Information. At the top right of the Thunderbird window, click the menu button , then select Help > Troubleshooting Information. Press the Copy text to clipboard button and paste the information into your reply.

Thanks -here's the info

i don't know what account 2 is - might that be significant?

 Application Basics

   Name: Thunderbird
   Version: 45.4.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20160928132736
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) mail.btinternet.com:995, SSL, passwordCleartext
     OUTGOING: , mail.btinternet.com:465, SSL, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (pop3) pop.gmail.com:995, SSL, passwordCleartext
     OUTGOING: , smtp.gmail.com:465, SSL, passwordCleartext, true

 Crash Reports

 Extensions
   Lightning, 4.7.4, false, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.filesystem_reported: 1
     browser.cache.disk.smart_size_cached_value: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     dom.apps.reset-permissions: true
     extensions.lastAppVersion: 45.4.0
     font.name.monospace.el: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Consolas
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Calibri
     font.name.serif.el: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Cambria
     font.size.fixed.el: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 17
     gfx.crash-guard.glcontext.appVersion: 45.4.0
     gfx.crash-guard.glcontext.deviceID: 0x0412
     gfx.crash-guard.glcontext.driverVersion: 20.19.15.4444
     gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: true
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true
     gfx.crash-guard.status.glcontext: 2
     mail.openMessageBehavior.version: 1
     mail.winsearch.enable: true
     mail.winsearch.firstRunDone: true
     mail.winsearch.global_reindex_time: 1476042665
     mailnews.database.global.datastore.id: 717e9913-e97e-44cf-96dc-d7346c3f1cc
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1476993878
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true

 Graphics

     Adapter Description: Microsoft Basic Display Driver
     Vendor ID: 0x00ba
     Device ID: 0x00ba
     Adapter RAM: Unknown
     Adapter Drivers: Unknown
     Driver Version: 10.0.14393.0
     Driver Date: 6-21-2006
     Direct2D Enabled: Blocked for your graphics card because of unresolved driver issues.
     DirectWrite Enabled: false (10.0.14393.321)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: Blocked for your graphics card because of unresolved driver issues.
     GPU Accelerated Windows: 0. Blocked for your graphics card because of unresolved driver issues.

     AzureCanvasBackend: skia
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: cairo

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.12
     4.12

     NSS
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS Util
     3.21.1
     3.21.1

     NSS SSL
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS S/MIME
     3.21.1 Basic ECC
     3.21.1 Basic ECC

So it looks like Lightning is causing some problems.

What calendar(s) are you using - local or network?

When does the 'not responding' issue occur? When starting Thunderbird, just out of the blue while using Thunderbird, or when you're using the calendar?

Lightning is disabled, via the TB safemode dialogue box . Can I completely remove Lightning and try reinstalling Lightning?

I have not yet managed to add a calendar to Lightning. I hope to use the calendars created in Windows Live Mail.I alreadyi have the instructions for this

TB is "not responding" when first started.

Thanks for your continuing help

You can uninstall Lightning for the time being. Note, you'll need to restart Thunderbird for this.

You can re-install it at any time from AMO. https://addons.mozilla.org/thunderbird/addon/lightning/

Another restart will be required then.

Just re-installing would eventually fix things already.

Hi christ1 - thanks

Have run win 10 and tb both in safemode and using the add-on manager have removed lightning.

Rebooted in normal mode and tb appears to work OK - can send and receive emails

Tried to add lightning from add on manager and this causes the program to give "not responding" message

What do you suggest now, please

Do you actually use Lightning? If not, you could just leave it disabled for the time being. I don't have a real solution for this right now.

This is a suggestion from another Thunderbird support contributor. I don't use Win10, so I won't be able to help with this any further.

I would guess that there’s an incompatibility between Lightning and the graphics driver (MS Basic Display Adapter). The user is on W10, probably an old laptop that was upgraded to 10, and the standard upgrade found no better driver than the Basic one. I run W10 on a few 10-year-old systems, but it sometimes takes a bit of sorcery to find and install a video driver that uses most, if not all of the capabilities of the graphics hardware. I would recommend the user try to install the W7, 8 or even Vista driver if possible. They might even be lucky and do the update from Device Manager.

Hi christ1

Thanks for your later posts.

After many re-installs I managed to identify the ics file created by WLM 2012 calendar as the culprit. I have managed to add Google calendar via ics file into Lightning so I suppose that WLM ics file is corrupt, unless the file is too big for TB?

So thanks again and I'll mark the question of "Not Responding" as answered