When you create a project with Madcap Flare Snippet files (*.flsnp) or you add *.flsnp file(s) in an existing project, they are added as a reference file(s).
See the screenshot below:
If you try to change the file usage, the error message below occurs:
Resolution
To make Madcap Flare Snippet files translatable and to be recognized by Studio, go to Files Types -> XML: MadCap Compliant -> and manually add *.flsnp and *.fltar extensions in File dialog wildcard expression field.
