I noticed that pressing the "Save As" button when Exporting an Image generates an exception (see below):

17:27:20.807 ERROR c.l.image.exporter.ExportDialog - String index out of range: -1
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(Unknown Source) ~[na:1.8.0_40]
at com.lorainelab.image.exporter.ExportDialog.saveAsButtonActionPerformed(ExportDialog.java:314) ~[image-exporter-8.4.0.jar:na]
at com.lorainelab.image.exporter.ExportDialogGui.lambda$addMainPanel$1(ExportDialogGui.java:72) [image-exporter-8.4.0.jar:na]
at com.lorainelab.image.exporter.ExportDialogGui$$Lambda$180/791740842.actionPerformed(Unknown Source) [image-exporter-8.4.0.jar:na]
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) [na:1.8.0_40]
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) [na:1.8.0_40]
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) [na:1.8.0_40]
at javax.swing.DefaultButtonModel.setPressed(Unknown Source) [na:1.8.0_40]
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) [na:1.8.0_40]
at java.awt.Component.processMouseEvent(Unknown Source) [na:1.8.0_40]
at javax.swing.JComponent.processMouseEvent(Unknown Source) [na:1.8.0_40]
at java.awt.Component.processEvent(Unknown Source) [na:1.8.0_40]
at java.awt.Container.processEvent(Unknown Source) [na:1.8.0_40]
at java.awt.Component.dispatchEventImpl(Unknown Source) [na:1.8.0_40]
at java.awt.Container.dispatchEventImpl(Unknown Source) [na:1.8.0_40]
at java.awt.Component.dispatchEvent(Unknown Source) [na:1.8.0_40]
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) [na:1.8.0_40]
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) [na:1.8.0_40]
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) [na:1.8.0_40]
at java.awt.Container.dispatchEventImpl(Unknown Source) [na:1.8.0_40]
at java.awt.Window.dispatchEventImpl(Unknown Source) [na:1.8.0_40]
at java.awt.Component.dispatchEvent(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue.dispatchEventImpl(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue.access$500(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue$3.run(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue$3.run(Unknown Source) [na:1.8.0_40]
at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_40]
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) [na:1.8.0_40]
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue$4.run(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue$4.run(Unknown Source) [na:1.8.0_40]
at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_40]
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) [na:1.8.0_40]
at java.awt.EventQueue.dispatchEvent(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [na:1.8.0_40]
at java.awt.EventDispatchThread.run(Unknown Source) [na:1.8.0_40]