fix for ie11

src/extensions/print/bootstrap-table-print.js

@@ -173,6 +173,8 @@ $.BootstrapTable = class extends $.BootstrapTable {
     const table = buildTable(data, this.options.columns)
     const newWin = window.open('')
     newWin.document.write(this.options.printPageBuilder.call(this, table))
+    newWin.document.close()
+    newWin.focus()
     newWin.print()
     newWin.close()
   }