if (viewport.hasHiddenColumns() && viewport.getSelectionGroup() != null)
{
- copiedHiddenColumns = viewport.getAlignment().getHiddenColumns()
- .getHiddenColumnsCopy();
+ copiedHiddenColumns = new Vector<>(viewport.getAlignment()
+ .getHiddenColumns().getHiddenColumnsCopy());
int hiddenOffset = viewport.getSelectionGroup().getStartRes();
for (int[] region : copiedHiddenColumns)
{