there is 2 possible reasons for this: 1. the file simply cannot be launched at all because the file is fake, corrupt, or not available to be previewed. you may also not have the correct codecs required to launch this file. 2) you got a beta version that had that launching capability broken by mistake. get an update version.

the license popup message that LW gives you has nothing to do with actual license acquisition. LW only detects certain Licenses and presents this popup to keep their arses alive. in general, you should tick always use this answer and click yes.