when i download the schematic of my plot only have 0 bytes and i cant use in my sv because there are this error 'schematic could not read or it does not exist: null' please help me
This'll be because PlotSquared has a stupidly small max file size on downloads. What world are you using to download the build? If it's Commission world, use /plot web download world and then use mcedit to export it to a schematic. We should soon have our own download page running which will have a respectable file size limit.