SQL Developer Data Modeler

I'm stroke by misfortune and hope to get some help.

Using: Oracle SQL Data Modeler; Version 3.1.1.703 in 64 Bit version

Situation
After some efforts I managed to install a SVN_repositry and checked in all files of my model directory ..\models\LPNO_models Vxx. Unfortunately the file MODEL_X.DMD is not saved in that repositry, as it was located in the folder ..\models not in ..\models\model_XX. I didn't want to checkin all the files from folder ..\models because there is a lot of older subfolders full of stuff I didn't want to be stored in the SVN.

After a restart of SDM I got stroke by a problem I already had once: The menues got corrupted, not FILE>OPEN dialogs nomore.
Acording to post https://forums.oracle.com/forums/thread.jspa?threadID=2212067 I deleted
C:\Users\YOUR_WINDOWS_USER\AppData\Roaming\Oracle SQL Developer Data Modeler.

After restarting SDM the menus were there again. Then I wanted to open my model MODEL_X.DMD. After opening it, the design was empty, everything lost!!?

What happend? Who can I regain my design?

I got one DMD-File LPNO_models V20.dmd that looks like that


+<?xml version = '1.0' encoding = 'UTF-8'?>+
+<OSDM_Design class="oracle.dbtools.crest.model.design.Design" name="LPNO_models V20" id="7D9FB226-808A-374A-8E2D-704DD288C9B3" version="3.5">+
+<createdBy>olippuner</createdBy>+
+<createdTime>2011-09-14 21:26:08 UTC</createdTime>+
+<comment>englisch Entitäten und Felder</comment>+
+<ownerDesignName>LPNO_models</ownerDesignName>+
+<capitalNames>false</capitalNames>+
+<designId>7D9FB226-808A-374A-8E2D-704DD288C9B3</designId>+
+</OSDM_Design>+

and I have the subfolder in the filesystem and in the SVN-Repositry that should contain the model data. All trials to reopen this project result in displaying an empty model to me.
I can open an very old model version LPNO_models V19 and everything is fine, logical model is contained and displayed. But I can't work with that old state. There is also no actual model on the DB that I could reengineer.

Question
How does the DMD-File LPNO_models V20.DMD cooperate with the data in the subfolger "LPNO_models V20"?
Is there a way to get the both in synch again?
Is there a way to rebuild the LPNO_models V20.DMD from the subfolder data? (I guess the subfolder data is still ok, and I guess the LPNO_models V20.DMD is corrupted, out of synch or something like that)

Help for regaining control over my model and about the does and dont's in model data handling and organisation is appreciated.
Thanks.