The one with the signature "[@ nvwgf2umx.dll ]" is a crash while interacting with an Nvidia driver. The notes say: "|[0][GFX1-]: DXVA2D3D11 video decoding is disabled due to a previous crash. (t=53.121) |[1][GFX1-]: DXVA2D3D9 video decoding is disabled due to a previous crash. (t=53.121) |[2][GFX1-]: DXVA2D3D11 video decoding is disabled due to a previous crash. (t=53.1678) |[3][GFX1-]: DXVA2D3D9 video decoding is disabled due to a previous crash. (t=53.1678)." It sounds as though this has been a problem in the past, but I'm not sure whether there is a quick solution. We usually suggest this article, which lists safe sites to check for an update: [[Upgrade your graphics drivers to use hardware acceleration and WebGL]]. The other one has the signature "[@ CAudioClient::FinalRelease ]" and seems to be related to stopping audio. I don't know why that would be triggered right away rather than when you paused or closed the video. Are these problems on YouTube? In that case, please try disabling your YouTube-specific extensions to see whether having NONE of them enabled allows you to play videos normally. If that works, you can try enabling one at a time and testing to see whether a particular one might be causing the issue. Here's how: You can view, disable, and often configure or remove unwanted or unknown extensions on the Add-ons page. Either: * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons * type or paste '''about:addons''' in the address bar and press Enter/Return In the left column of the Add-ons page, click Extensions. Then cast a critical eye over the list on the right side. Any extensions that Firefox installs on its own are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything you don't recall installing or no longer need? I suggest disabling these three as a test: * Magic Actions for YouTube™ (ver. 6.9.1.2) * Stop AutoPlay Next for YouTube™ (ver. 0.1.6) * YouTube High Definition (ver. 52.0.3) Often a link will appear above at least one disabled extension to restart Firefox before the change takes effect. You can complete your work on the tab and click one of the links as the last step. Any improvement/can you track it down?