I made a 40 min video and added few photos but when I clicked save it keeps coming up with "could not find file". On the scrollable tap on the bottom the videos are all shown with a black thumbnail however, when I click play the video plays fine on the big screen but on the bottom screen all videos are shown in black.
I say this, because it sounds like a memory issue, as in PhotoVidShow is running out of it. We improved memory usage in PhotoVidShow a few versions back, so worth updating. Memory issues may occur if an user is importing large amounts of HD video or even a 4k video into PhotoVidShow.
Also if you could attach your PhotoVidShow log file, this may tell us more (log.txt file)
This will be a file on your PC called 'log.txt' and it will be stored in the folder 'Documents/PhotoVidShow' on your PC. I.e. right click on 'Start', select 'File Explorer', then in that File Explorer window, select 'Documents' and then select the 'PhotoVidShow' sub folder to locate the log file.