Thank you for including the picture. That is very helpful. It seems that you have the TeX notation filter enabled, but that the an error is occuring with generating images. If you want to use the TeX filter, you need to make sure correct binaries are available. Check the documentation for that plugin.
You may prefer to use the MathJaxloader filter instead. Again check that it is properly configured before using the editor. You should not use both MathJax and the TeX filter. The TeX filter will override the Mathjaxloader.