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Thunderbird Version 78 - CalDav calender not working with error PROPFIND "405 Method Not Allowed".

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  • Last reply by rde

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Since the update to Thunderbird 78 my CalDav calender cannot be activated anymore. It appears grey in the calendar list. I checked on multiple computers and my colleagues have the same problem. Is there a way to fix this?

Since the update to Thunderbird 78 my CalDav calender cannot be activated anymore. It appears grey in the calendar list. I checked on multiple computers and my colleagues have the same problem. Is there a way to fix this?

Modified by Wayne Mery

Chosen solution

It turns out that it was indeed related do the UserAgent being rejected by the CalDav-Server after the update to version 78. In that version Lightning is part of Thunderbird and not shown in the user-agent string.

A workaround would be to manually override the general.useragent.locale string in settings with an old one.

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Hi, It didn't worked for me either and I have switched back to 6.8 version. You should wait till the authors update that add-on or you might switch back to an old version.

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The error-message ist PROPFIND "405 Method Not Allowed". Is it possible that it has something to do with the user agent that differes in version 78 from version 68 and therefore the client ist no longer accepted?

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Chosen Solution

It turns out that it was indeed related do the UserAgent being rejected by the CalDav-Server after the update to version 78. In that version Lightning is part of Thunderbird and not shown in the user-agent string.

A workaround would be to manually override the general.useragent.locale string in settings with an old one.

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actually that's not a solution. but since your topic is marked solved i opened a new topic for the problem: https://support.mozilla.org/en-US/questions/1323344