【APPCenter】Crash编号：103 -- 修复

PDF Office/PDF Master/Class/PDFWindowController/ViewController/KMMainViewController+Action.swift

@@ -2461,7 +2461,8 @@ extension KMMainViewController {
                 }
             }
         } else {
-            let file: URL = (self.myDocument?.fileURL)!
+            guard let url = self.myDocument?.fileURL else { return }
+            let file: URL = url
             if FileManager.default.fileExists(atPath: file.path) {
                 NSWorkspace.shared.activateFileViewerSelecting([file])
             }