We are using IJC to edit structures which display valence errors.
I have included an example in the attached document.
The molecule is modified, however, IJC does not seem to register the modification and Save is still disabled.
So we have to edit the molecule slightly to make sure 'Save' is enabled again.
Let me know if this should be reported as a Marvin issue.
We are using IJC and Marvin 5.3.1