Hi, tumbleweed firefox 129.0.1 i know it was working about 1 to 2 years in past, some update has changed this. and yes, it could be that the file is not really correct at the server. i got this error also from other sources especially when i use different nitter instances. changing the nitter instance shows video's which has this error at other instances before. is there something i could configure at my computer/firefox that the mimetype will be set correct according to the ending of the filename and the video will be played? here a own movie where i am pretty sure it was working before. https://www.becherer.de/Homepage/Kloepper/cobot-schweissen.MOV it shows the error "no video with supported mime-type" off topic: yes, for the technicians here, the machine is not adjusted perfect, to many sparks. simoN -- www.becherer.de