This issue affects users of NFS file systems only.
The IQTMP16 environment variable does not point to a local directory. Each client connection creates several directories and files in a temporary directory. SAP Sybase IQ deletes these files when the connection ends. If IQTMP16 does not point to a local directory, it cannot find the .nfs* files that NFS creates.
Set IQTMP16 to a local directory and restart the server.