Go to Tools>Options>Uploads>Basic & untick the option for Partial File Sharing & press the Apply button. Then you should be able to delete the file. Normally a file will attempt to verify for a maximum of 6 times before giving up but if it's crashing LW then ... delete it.

You might need to quit LW for this it to allow you.

If you wish to continue partial file sharing afterwards then go back & change it back.