Fix migration issue for split and zipped model files

plugins/org.eclipse.app4mc.amalthea.converters.common/src/org/eclipse/app4mc/amalthea/converters/common/MigrationHelper.java

diff --git a/plugins/org.eclipse.app4mc.amalthea.converters.common/src/org/eclipse/app4mc/amalthea/converters/common/MigrationHelper.java b/plugins/org.eclipse.app4mc.amalthea.converters.common/src/org/eclipse/app4mc/amalthea/converters/common/MigrationHelper.java
index 0f6f3e8..8b67526 100644
--- a/plugins/org.eclipse.app4mc.amalthea.converters.common/src/org/eclipse/app4mc/amalthea/converters/common/MigrationHelper.java
+++ b/plugins/org.eclipse.app4mc.amalthea.converters.common/src/org/eclipse/app4mc/amalthea/converters/common/MigrationHelper.java
@@ -464,9 +464,10 @@
 		Path inputPath = Paths.get(input.toURI());
 		byte[] buffer = new byte[1024];
 		try (ZipInputStream zis = new ZipInputStream(Files.newInputStream(inputPath))) {
-			// use the filename of the input file instead of the name of the zipentry to
-			// handle cases where multiple zipped model files are located in the same folder
-			// and contain model files with the same filename, e.g. SCA2Amalthea results
+			// read next ZIP file entry and position the stream at the beginning of the entry data
+			zis.getNextEntry();
+			// use the filename of the input file to handle cases where multiple zipped model files
+			// are located in the same folder (Zip entry name is typically "ResourceContents")
 			Path unzipped = Paths.get(inputPath.getParent().toString(), UNZIPPED_PREFIX + input.getName());
 			try (OutputStream fos = Files.newOutputStream(unzipped)) {
 				int len;