My Portable Thunderbird (2.0.0.14) starts up with the grey screen containing: ----^
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Thats a known issue.Removing the offline.manifest file from ThunderbirdPortable/App/thunderbird/chrome/ will make the gray box and red text issue disappear.
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Thanks for the reply. This solved my problem. I re-installed my computer, and thought I would try using the Portable versions of applications for a while, including Thunderbird and Firefox.
Thank you for the prompt reply. I can confirm that the solution works for me.
Stamos