I have windows 10, i7 10th gen, 16gb of ram and a Nvidia GeoForce MX250. I went through all the videos and steps to help make Pr show a preview. Nothing works. If I render it (which takes 10 min on 20 seconds of video) then I can see the video. I am not sure what is wrong.
After Effects is a little better. Media Encoder took 30 minutes to do a 20 second video. Do we need to have 32 gb of ram? I pay for a subcription and can't even use it.
Most laptops with an MX250 have only a low-power i7 CPU that has only 4 or 6 physical CPU cores and very low sustainable clock speeds on all cores. Worse, the MX250 itself has no NVDEC or NVENC support at all whatsoever due to the chip that it uses (in this case, a variation of the GP108 GPU that is used in the budget desktop GeForce GT 1030). And the GP108 chip does not have NVENC present at all, while NVDEC is disabled on the laptop MX-series GPUs during chip manufacture.
And since Adobe defaults to using Nvidia hardware over Intel whenever any discrete Nvidia GPU is detected on the creation of a new project, this means that exporting H.264 and HEVC will default to using software-only encoding because there is no hardware encoder at all in the MX250. And this will take a very long time on underpowered laptops such as yours.