Problem is caused when refreshing markup using Ajax and in data is special character ().
Error occurs in my project everywhere when refreshing markup using Ajax where this special character occurs.
I create and attach quickstart project which reproduces this problem in simple way: changing markup through hiding/showing TextField by ajax button.
Steps to reproduce problem:
1. Download and run attached quickstart project
2. Enter to TextField symbol presented under "Insert this string for error..." label:
3) Click „Regular submit” twice (this causes component to refresh, but doesn’t cause error)
4) Now click „Ajax submit” twice – this causes button to not refresh markup and show error: