You have a (grace, invisible, muted) chords and rests before the time signature.
!NoteWorthyComposerClip(2.751,Single)
|Clef|Type:Treble
|User|RangePitchMarker.hmm|Pos:7|Class:Span|Color:1
|Chord|Dur:Half,Grace|Pos:-6,6|Opts:Stem=Down,Lyric=Never,Muted|Visibility:Never
|Rest|Dur:Half,Grace|Visibility:Never
|User|RangePitchMarker.hmm|Pos:7|Class:Span|Color:7
|Chord|Dur:Half,Grace|Pos:-5,4|Opts:Stem=Down,Lyric=Never,Muted|Visibility:Always
|Rest|Dur:Half,Grace|Visibility:Always
|User|RangePitchMarker.hmm|Pos:7|Class:Span|Color:2|Visibility:Always
|Chord|Dur:Half,Grace|Pos:-2,1|Opts:Stem=Down,Lyric=Never,Muted|Visibility:Always
|Bar|Visibility:Always
|Boundary|Style:Reset|Visibility:TopStaff
|User|PageTxt.nw|Pos:0|Fnt:PageTitleText|PgCtrl:Once|XLoc:Center|PgStyle:Title|YLoc:Top|Text:%Title%|Visibility:TopStaff
|User|PageTxt.nw|Pos:0|Fnt:PageText|PgCtrl:Once|PgStyle:Author|Text:%Author%|YLoc:Top|CY:10|XLoc:Right|Visibility:TopStaff
|User|PageTxt.nw|Pos:0|Fnt:PageText|YLoc:Top|CY:4|PgStyle:Lyricist|XLoc:Left|Text:%Lyricist%|Visibility:TopStaff
|User|PageTxt.nw|Pos:0|Fnt:PageSmallText|YLoc:Bottom|CY:-6|PgStyle:Copyright|XLoc:Center|Text:%Copyright1%%br%%Copyright2%|Visibility:TopStaff
|User|Acciaccatura.ms|Pos:0|Class:StaffSig
|User|CueHeads.ms|Pos:1|Class:StaffSig|Size:70
|User|Melismatic.nw|Pos:0|Class:StaffSig
|Key|Signature:F#|Tonic:G
|TimeSig|Signature:2/4
!NoteWorthyComposerClip-End
My convertor doesn't seem to like that.