Undetermined I/O failure Undetermined I/O failure LittleMissMaya (Programmer) (OP) 24 Sep 12 11:05 has anyone ever gotten this error? We are trying to write a large xml file to our server based on a PC Sas output. Any suggestions would be appreciated. Thanks! Michelle RE: Undetermined I/O failure ChrisW75 (Programmer) 12 Mar 13 21:22 SAS isn't so good at resolving external errors. Could be lack of disk space, could be network connectivity glitches. I've found in the past that if this keeps happening, it's worth working on your local disk, then copying the data across using file system tools (ie doing it through your OS or a script or something). If it's something that is done regularly and you want it automated through SAS, you can use the X command to access OS command line commands. Chris Business Analyst, Code Monkey, Data Wrangler. SAS Guru.