stata16，outreg2循环报错too few quotes

用stata16搞实证，走到最后这一步报错了，有两个too few quotes 、too few quotes，

代码

tsset stkcd year
reg Zhang_Z tone
outreg2 using myfile, excel replace stats(coef tstat) aster(coef)
reg AltmanZ tone
outreg2 using myfile2, excel append stats(coef tstat) aster(coef)

运行结果及报错内容

.