Symptom:
Package runs fine in SSDT (VS 2015), fails in production SQL Agent (SQL 2016) with:
The package format version is not valid. (SSIS 2016 expected version 6, found 5)
Root cause:
ssis6 upd missing in .dtsx because developer copied file from old server without upgrade.
Fix:
dtutil /file "package.dtsx" /upgrade /destfile "package_v6.dtsx"
Resulting file contained ssis6 upd + version 6 → deployment succeeded.
"SSIS6 UPD" appears to be an abbreviated reference combining: ssis6 upd
Taken together, "SSIS6 UPD" most plausibly denotes an update/patch (UPD) for a versioned SSIS product or an internal release named “SSIS6.” Below is a comprehensive, well-structured explanation covering possible meanings, typical contents, installation guidance, troubleshooting, and best practices.
Open a .dtsx (XML) after upgrade. Look for: Symptom: Package runs fine in SSDT (VS 2015),
<DTS:Property DTS:Name="PackageFormatVersion">6</DTS:Property>
<DTS:Property DTS:Name="VersionComments">ssis6 upd</DTS:Property>
Older packages (non-upgraded) show:
<DTS:Property DTS:Name="VersionComments">ssis5</DTS:Property>