Firstly, always remember for decompression u should have
CLS-SREP.dll in the same folder where the arc.exe is.
If u got CLS-Srep.dll which is 86 Kb or 54 kb or something which is <100 kb then remember those only works during decompression if they are in the same folder where the arc.exe is during COMPRESSION then the arc simply throw disk full error or something other error
the above CLS-SREP.dll, works during compression too.