I was working on a complex model and was able to save it without errors or warnings. When I reopen it in the Editor, only the part to the right of the diagram is displayed correctly. A third of the elements are crammed to the left border and I cannot expand the screen to the left or the right any more.
This behaviour occurs when your diagram exceeds an undocumented width limit. You should actually be notified about this condition when you save the diagram. This is a known issue and has already been forwarded to our developers. If you are affected by this issue and want to be kept up to date about this issue, please create a ticket in our Support Portal and reference the ticket number SPM-11219.
The information within the diagram is not lost though. You can recover the diagram by splitting it in two and will notice that all elements are aligned correctly.
KBA , BPI-SIG-PM-MOD-EDT , Graphical Editor for SAP Signavio Process Manager , Known Error