Thanks for your posting and using Aspose.Cells for Java.
We were able to replicate this exception using the latest version. Below is a sample code for a reference.
We have logged this issue in our database. We will look into it and fix it. Once the issue is resolved or we have some other update for you, we will let you know asap.
Exception Exception in thread "main" com.aspose.cells.CellsException: Shape to image Error! at com.aspose.cells.At.a(Unknown Source) at com.aspose.cells.Workbook.a(Unknown Source) at com.aspose.cells.Workbook.save(Unknown Source) at com.aspose.cells.Workbook.save(Unknown Source) at ClsAsposeTest.f1(ClsAsposeTest.java:47) at ClsAsposeTest.main(ClsAsposeTest.java:26)