Hello there kelvin 19421. We have read your message. We try To help you. the problem that occurs when you see the popup window with the message is a notification about your operating system. It is not that there is something wrong with Thunderbird but with what Thunderbird uses. It may be that it is damaged or missing. Its not a common missing library. Common missing libraries are : Commonly-missed libraries include:(Linux). libgl1-mesa-glx or libgl1 libglib2.0-0 libjpeg62 libpng12-0 libsm6 libtiff5 libx11-6 libxcb1 libxrender1 Missing libraries may cause errors beyond what is suggested by their name. The PdCom library shall provide a flexible C++ API for exchange of process data. It is designed to be independent of any communication protocols and channels, and shall be usable under several operating systems and platforms. I. e. it has been tested successfully under Linux and Windows. With the reinstallation with everything that is on your computer machine it will automatically be reinstalled. Also a refresh of your system could do something in the right direction. After that, installing a new installation of Thunderbird on the updated system, the problems will have changed considerably. also use a good antivirus. Some systems can be hacked. And are so vulnerable places for loss and damage. Keep updating your system. It could be that To. P.s. https://www.etherlab.org/download/pdcom/ Greetings firefoxvolunteer.