My Process model (published )keeps on resetting the layout and connection lines

Relevant error:
19:26:51,880 INFO [stdout] (http-/0.0.0.0:8080-14) 2014-07-17 19:26:51,878 [http-/0.0.0.0:8080-14] ERROR com.appiancorp.process.design.service.ProcessDesignServiceXmlImpl - An error occurred retrieving the model from the filesystem.
19:26:51,886 INFO [stdout] (http-/0.0.0.0:8080-14) com.appiancorp.suiteapi.common.exceptions.AppianException: Invalid Type: null (APNX-1-4047-000)

This error indicates the model is referencing a CDT that was deleted and reuploaded with a DIFFERENT NAMESPACE

To recover from this situation:

1. DO NOT Save and Publish the broken look and feel, if you already did then this is going to remain since you are basically saving what you see on the screen.
2. Reupload the deleted CDT which changed its namespace
3. If you never saved and published the broken look and feel then reopening the model at this point will fix the issue.
4. Remap the model to point to the new CDT (we don't care about the reuploaded one, we are just using it to let us remap).
5. Save and publish the updated model
6. You can now delete the unused CDT if not used by other models

Remember that impact analysis only updates data types that remain named and namespaced the same. CDTs are considered unique based on their name and namespace, changing the namespace of a CDT is basically breaking the association with the previous CDT considering this one a completely new and separate one.

Relevant error:
19:26:51,880 INFO [stdout] (http-/0.0.0.0:8080-14) 2014-07-17 19:26:51,878 [http-/0.0.0.0:8080-14] ERROR com.appiancorp.process.design.service.ProcessDesignServiceXmlImpl - An error occurred retrieving the model from the filesystem.
19:26:51,886 INFO [stdout] (http-/0.0.0.0:8080-14) com.appiancorp.suiteapi.common.exceptions.AppianException: Invalid Type: null (APNX-1-4047-000)

This error indicates the model is referencing a CDT that was deleted and reuploaded with a DIFFERENT NAMESPACE

To recover from this situation:

1. DO NOT Save and Publish the broken look and feel, if you already did then this is going to remain since you are basically saving what you see on the screen.
2. Reupload the deleted CDT which changed its namespace
3. If you never saved and published the broken look and feel then reopening the model at this point will fix the issue.
4. Remap the model to point to the new CDT (we don't care about the reuploaded one, we are just using it to let us remap).
5. Save and publish the updated model
6. You can now delete the unused CDT if not used by other models

Remember that impact analysis only updates data types that remain named and namespaced the same. CDTs are considered unique based on their name and namespace, changing the namespace of a CDT is basically breaking the association with the previous CDT considering this one a completely new and separate one.