Hi everyone, I am trying to validate topology for a polyline feature class with 600.000 records but I am getting an error "Validate Topology failed. A failure was detected inside the topology engine overlay processor. [error id:220]". I have searched on ESRI page and I found that this error was fixed with a patch aplied on the SP2 and was included in SP3. Despite trying both fixes I still get the error. I have checked the geometry - it's ok. I have used enterprise GDB instead of file GDB - no result. Reading this forum I suspect it's related with the way I have cracked the ArcGIS 10 - old way with AfCore.dll replacement. Does anyone had encountered the same problem ? - What is your advice ?