There is any way in the software to convert Mr SID files From Gen 4 to Gen 3?

[PauloMartinez]

I want to convert Mr SID gen 4 to Mr SID gen 3

[DanPatterson]

From here... they can be read, but not converted between

Raster file formats—ArcGIS Pro | Documentation 

You would have to see the LizardTech link in there.