What happens to ploneformgen data if it is upgraded to higher version from 1.7.1 to 1.7.17?

Question

I have an existing Plone site 4.1.4 with Ploneformgen 1.7.1 working from 2 years on a Linux stand alone install . From last 15 days, it has not been coming up on the browser, though I see it running with ./bin/plonectl fg in a screen. It shows different logs every-time. All I do is restart it all over again till it comes to a halt after 2-3 hours. The latest error log I got:

2015-01-09 10:58:12 ERROR Zope.SiteErrorLog 1420781292.380.372194570069 http://example.com:8081/site/checklist/tinymce-save
Traceback (innermost last):
  Module ZPublisher.Publish, line 126, in publish  
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 46, in call_object
  Module Products.TinyMCE.browser.browser, line 33, in save
  Module Products.TinyMCE.adapters.Save, line 18, in save
AttributeError: 'NoneType' object has no attribute 'set'

2015-01-09 11:01:06 ERROR Zope.SiteErrorLog 1420781466.020.201924322182 http://example.com:8081/site/checklist/tinymce-save
Traceback (innermost last):
  Module ZPublisher.Publish, line 126, in publish  
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 46, in call_object
  Module Products.TinyMCE.browser.browser, line 33, in save
  Module Products.TinyMCE.adapters.Save, line 18, in save
AttributeError: 'NoneType' object has no attribute 'set'

2015-01-09 17:20:31 ERROR ZServer Bad HTTP request: 'h'

What could be the problem? Also what could be the effect on the existing data if I upgrade ploneformgen to higher version from existing 1.7.1 to 1.7.17?