The mechanical compactor appears to have the same issue with ToP as #258; the erroring tooltip is shown only as long as there are items in its input inventory/block - the output section of the machine is unaffected

To test this, just place a Mechanical Compactor down and fill it with any accepted item

Tested on Forge version 14.23.5.2847, Athenaeum 1.17.3, Dropt 1.15.1, Patchouli 1.0-19, Pyrotech 1.4.15 and Theoneprobe 1.4.28