Using licensed VP 3.52 on Windows 8.1 on a Lenovo Core 7 notebook with 8 GB memory. I've created a 9 minute sequence consisting of about 60 clips. Had been creating "trial" versions of the final rendering during its development, and final output file size grew to 228 MB. Output is .AVI, H264, and YouTube 720P. Everything appeared OK until yesterday.
Many of the frames of yesterday's trial were corrupted - they appeared "solarized" - and many of the text overlays failed to appear, although the full sequence was rendered. Tried again, but VP crashed about 10% of the way thru rendering. Tried several times, with crashes occurring at different locations in the sequence. Frustrated, I put it aside for the night.
Tried again this morning, and the full sequence rendered properly (file size 228 MB) in about 16 minutes. Immediately tried again, and the rendering took about 5 minutes with file size about 35 MB. Tried a third time and it took about 16 minutes to complete the rendering. File size is 235 MB compared to previous 228 MB, and a few frames were "solarized". This is without making any changes to the project file.
I suspected overheating, so I installed a hardware temperature monitor. CPU is stable at about 70 C, while GPU is stable at about 45 C.
What could explain the unpredictable behaviour? How can I ensure that VP will correctly render the output?