Latex Erorr: Missing \begin{document}

[jhfanseu]

请问最近总显示Latex Erorr: Missing \begin{document}是咋回事????

[juneshi0315]

同样的问题，运行时错误信息如下：
This is XeTeX, Version 3.14159265-2.6-0.99998 (MiKTeX 2.9.6300 64-bit) entering extended mode (thesis.tex LaTeX2e <2017-04-15> Babel <3.9r> and hyphenation patterns for 1 language(s) loaded. (seuthesix.cls Document Class: seuthesix 2016/03/20 1.0.1 The LaTeX template for academic degr ee thesis of Southeast University Document Classseuthesix' 1.0.1 by James Fan (2016/03/20)
[seuthesix]: Load seuthesix.cfg successfully!
(seuthesix.cfg

! LaTeX Error: Missing \begin{document}.

See the LaTeX manual or LaTeX Companion for explanation.
Type H for immediate help.
`

有人知道怎么解决吗？