Saving project file with GeoLayout and an active column throws exception

[mbastian]

Expected Behavior

Project is saved properly and the column selected in the layout is selected again when loading the project.

Current Behavior

[INFO] SEVERE: Error while writing XML workspace persistence provider 'layoutmodel'
[INFO] java.lang.NullPointerException
[INFO] 	at com.ctc.wstx.sw.BaseStreamWriter.writeCharacters(BaseStreamWriter.java:458)
[INFO] 	at org.gephi.layout.LayoutModelImpl.writeXML(LayoutModelImpl.java:244)
[INFO] 	at org.gephi.layout.LayoutModelPersistenceProvider.writeXML(LayoutModelPersistenceProvider.java:64)
[INFO] [catch] at org.gephi.project.io.GephiWriter.writeWorkspaceChildren(GephiWriter.java:144)
[INFO] 	at org.gephi.project.io.SaveTask.writeWorkspaceChildrenXML(SaveTask.java:279)
[INFO] 	at org.gephi.project.io.SaveTask.run(SaveTask.java:153)
[INFO] 	at org.gephi.desktop.project.ProjectControllerUIImpl$3.run(ProjectControllerUIImpl.java:152)
[INFO] 	at org.gephi.utils.longtask.api.LongTaskExecutor$RunningLongTask.run(LongTaskExecutor.java:278)
[INFO] 	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
[INFO] 	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[INFO] 	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
[INFO] 	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
[INFO] 	at java.base/java.lang.Thread.run(Thread.java:829)

Steps to Reproduce

1. Install the GeoLayoutPlugin and load an example file with lat/lon column
2. Select the GeoLayout and make sure the lat/lon column are selected in the property sheet
3. Save the project
4. Exception when project saved

Your Environment

• Version used: Gephi 0.9.6
• Operating System: Mac OS