In web editor when try to save diagrom the excepion is got:
Some exceptions are raised while trying to save your diagram. Please try again. If the problem resides, please contact the Signavio Support via the envelope symbol in the toolbar.
In the name of process of bpmn file the " symbol exists. It's a reason. When removed everything works fine.
Using the same " symbol in other components, seems to work well.
Nothing in the log file.