Grails GSP edit: code analysis breaks, unable to type certain characters

After editing a GSP page for a while, the code analysis sometimes breaks and stops updating. Usually while in the middle of editing a tag, while the syntax is invalid, it will highlight in red, then suddenly all of the rest of the page will be shown as invalid syntax (red underline). No amount of editing will fix it. Closing and opening the file will not fix it. The Code Analysis eye icon is open but does not seem to be updating.

A similar but different issue sometimes happens also while editing GSP pages: Suddenly I can no longer type certain characters (space, newline, left-angle-bracket, etc). Some characters work but not others. Also: double-clicking or "Extend Selection" action do not work anymore.

This seems to happen more often after editing Javascript in a page, but not always.

These errors did not occur in the previous version I had.

Grails 2.4.4 application.
Mac OS X Sierra
IntelliJ IDEA 2016.2.5
Build #IU-162.2228.15, built on October 14, 2016
JRE: 1.8.0_112-release-287-b2 x86_64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o

---

*Imported from [IDEA-163552](https://youtrack.jetbrains.com/issue/IDEA-163552) · Type: Bug · Votes: 0*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

No source files, tests, or entry points are named. First reproduce the failure in a GSP page using the reported Grails 2.4.4 and IntelliJ IDEA 2016.2.5 setup, especially after editing JavaScript; done means code analysis resumes updating and spaces, newlines, angle brackets, selection, and double-click actions work normally.

Written by the indexing model from the issue text.