Perhaps post your preamble, or your (reduced) LyX file, or a LaTeX export of a reduced copy of your file. Supports checking spellings and autocorrect feature for creating error free documents. That you switched your laptop off and on, is just a coincidence, you probably have done something which you did not notice or remember. It is helpful and way better than simple Word documents for scientific publication writings, mathematical notations, for showcasing formulas, illustrations and tables. The LaTex documents when created through this software are very much stable and is not prone to crashes. The output file created as the LaTex document is way superior in quality than simple Word document.
It provides more intelligent interface than Word and help you in controlling the formatting. LaTex documents are portable options lighter than simple text files, it is extremely flexible in helping the users who are in academia or into researching and help them as it supports bibliography. It formats and highlights the different elements of your documents and improves the document style more than Word processing software tools.