Drifus Dreskeke

You're welcome. Thank you.

Right after I wrote the above post, I decided to enable/disable options for Thunderbird in Ccleaner. This issue only occurs when the cleaning option "Session" in Ccleaner - Thunderbird options is enabled.

Same problem here with Ccleaner 3.19. No problem with 3.18 Windows 7 x64 SP1 Thunderbird 12.0.1 Profile not on default place Extensions: Change quote and reply format 0.7.4.2 CompactHeader 2.0.5 Correct Identity 1.3.3 DOM Inspector 2.0.11 EditHtml 0.2.3.4 ExternalTemplateLoader 0.3.4.4 ImportExportTools 2.7.1.1 Lightning 1.4 MoreFunctionsForAddressBook 0.6.7.2 Provider for Google Calendar 0.13 SmoothWheel (AMO) 0.45.6.20100202.1 Verificador Ortográfico para Português do Brasil 1.8 ViewAbout 2.0.1 Xpunge 0.4.3 Plugins: None Appearance: Default theme with custom userChrome.css Ccleaner Thunderbird Options enabled: Internet Cache Internet History Cookies Session Compact Databases Steps to reproduce this issue: Without run Ccleaner after close Thunderbird (TB): open TB disable "Message Pane" or toggle off the "Quick Filter Bar" close TB open TB Actual Results: The Thunderbird opens with message pane or quick filter bar OFF/disable. Expected Results: The Thunderbird opens with the previous state maintained. In this case, message pane or quick filter bar OFF/disable. ________________ Running Ccleaner after close Thunderbird: open TB disable "Message Pane" or toggle off the "Quick Filter Bar" close TB run Ccleaner 3.19 open TB Actual Results: The Thunderbird opens with message pane ON and/or quick filter bar ON. Expected Results: The Thunderbird opens with the previous state maintained. In this case, message pane or quick filter bar OFF/disable.