There is only one file type that uses the .VMLT extension:
VAIO Video File
Video format used by the Picture Motion Browser (PMB) or Windows Movie Maker (WMM) utilities on Sony VAIO computers; stores video data converted from other video formats, such as .AVI and MPEG.
VMLT files often appear after a computer crash or a failed installation of a Windows service pack. When the correct codec is unavailable to play the PMB or WMM video project files, they are converted into a folder that contains a VMLT and .VMLF file. If this occurs, open the VMLT file with the GSpot utility, which tells you about the file and whether the codecs are installed.
NOTE: VMLT files are the same as VMLF files.
Updated: March 10, 2015