When u met the error code 8, u maybe used other languages other than English in your description.
So, u should firstly remove all contents in your description except which is English.
And then, after uploading, turning into ur mod's workshop page to change ur description by other languages.

当你遇到error code 8的时候，你可能在description里面写了非英语的其他语言。
所以你首先应该移除description里面的其他非英语的语言部分。
然后上传，最后到你的mod的创意工坊页面去用其他语言修改你的description。