What version of Premiere Elements are you using and on what computer operating system is it running?
You would need to
Consider converting the WTV video file to another format. If possible, try to convert to H.264.mp4, or H.264.mov, or MPEG2.mpg.
There are numerous converters found for this purpose in a Google Search . I have not used any of these WTV converters.
The formats mentioned are expected to be compatible for Premiere Elements import.