Hi. I´m running thunderbird 150.0 under win10 an a HP2760p with 8 GB RAM and 155 GB of free SDD-space. I´ve got the errormessage: "Nachrichten konnten nicht in die Mailbox-Datei geschrieben werden. Stellen Sie sicher, dass das Dateisystem Ihnen Schreibrechte einräumt und genügend Speicherplatz zur Verfügung steht, um die Mailbox zu kopieren." That is: Unable to write mesages to the mailbox-file. Make shure to have writing rights according to the filesystem and enaugh space is available to copy the mailbox. I can´t find a limitation to filesize. I deleted a lot of mails, the error persists. I updated from thunderbird 140 to 150.0. The error persists. I downloaded my emails on an win11 Laptop. The download stopped after a while with the same error. What can I do ? Thanks in advance - Robin