

You will also get to know if the files are corrupted. However, the app would fail to respond if any files are missing. When you do that, the app resets its settings and launches in its default state. You can try restarting the Thunderbird application. Moreover, a process might be running in the background hampering the working of Thunderbird. There might be a lock file that is preventing Thunderbird from running properly. Some temporary files, which are present on the server after the crash, are not letting you access the application. Also, if Thunderbird is not closed properly, it would have trouble starting.

So, when it detects multiple users, it fails to respond. Mozilla Thunderbird might be running at another location on the same profile. Causes of the Mozilla Thunderbird not Starting Issue But before moving on to the solutions, let’s take a look at the possible causes of this error. In this post, we’ll be discussing the solutions to fix this error. To open a new window, you must close the existing Thunderbird process or restart your system.” There are several reasons for this issue. The error message may appear like “Thunderbird is already running, but not responding. The application might be shown as running but will not be responding. While opening the Mozilla Thunderbird application, you might have encountered an error causing the application to hang.
