i tried to delete this page,
https://zh.wikisource.org/wiki/%E5%AE%87%E5%AE%99%E6%B5%AA%E5%AD%90
and it returns
[W5U8aApAADwAACsyA6UAAAAY] 2018-09-09 15:29:44: 类型“InvalidArgumentException”的致命例外
i tried to delete another similar page,
https://zh.wikisource.org/wiki/%E5%A4%A7%E9%A6%AC%E6%89%81
and it returns similar results, as
[W5U9XwpAIDEAAExgjJwAAAAA] 2018-09-09 15:33:51: 类型“InvalidArgumentException”的致命例外
there are some pages that link to a same website, so you can find them at
https://zh.wikisource.org/w/index.php?title=Special:%E9%93%BE%E6%8E%A5%E6%90%9C%E7%B4%A2&limit=500&offset=0&target=http%3A%2F%2Fopen-lit.com
i've also found that these pages have their first versions at Jan 15, 2001, several years before zh.wikisource was established. i wonder if these versions are the cause. so maybe this problem is linked with T123313.