I searched sourcelink for ALG0078 and found the following:
Error [ALG0078] Identical Name property value <property value>found on Hierarchical block instances <block instance> and <block instance>. The value should be unique for correct netlisting.
This error appears in case the "Name" property value is identical for one or more instances of a hierarchical block referring to same schematic view. For example, if you have placed two instances of Halfadder block say H1 and H2 in your top level design, the Name property value should be unique for each of the instances say Name = HalfaddedI nst1 for H1 instance and Name = HalfaddedInst2 for H2 instance.
In your case you have a block named 10G_port_no_mux on page 3 of your schematic, and an identically named block on page 12.
Hierarchical block names must be unique. You will have to rename one of the blocks.
I just tried an experiment on a hierarchical schematic and successfully renamed a block with the following proceedure;
1. Left click to select the block.
2. Right click and select edit properties.
3. in column A, select the name field.
4. Delete the existing name, and type a new name.
5. Close the editor
6. Save the page
7. Save the schematic.