Downloading problem

I am using the Play'a app on my PC and I had been downloading the vr files successfully (they go into folder created with the mp4, a preview file and a "poster" file) but after only a short time when I start a download it creates the folder and it shows the MP4 file for a brief time and then it will disappear. the poster file and the preview will be there but not the mp4 file. I will delete and try again and the same thing happens over again. I deleted the cache in the play'a app and I have deleted the download folders and still the same issue where the file download begins and creates a icon with a name such as: Full_A180_LR_U6k this will appear in the created folder but will disappear and the download progress bar goes all the way nearly complete and stops. Anyone know why this happens? frustrating because every time I try downloading this is the result now.