The error:
There was an exception while loading Script Task from XML: System.Exception: The Script Task uses version 14.0 script that is not supported in this release of Integration Services. To run the package, use the Script Task to create a new VSTA script. In most cases, scripts are converted automatically to use a supported version, when you open a SQL Server Integration Services package in %SQL_PRODUCT_SHORT_NAME% Integration Services. at Microsoft.SqlServer.Dts.Tasks.ScriptTask.ScriptTask.LoadFromXML(XmlElement elemProj, IDTSInfoEvents events)
I'm doing exactly what it says, but it does not help.
Any solution?
In the revised version of the SSDT (now 14.0.61x), there is a fix.
Install new version. (SSDT For download)
Right click project > Properties > Configuration Properties > General > TargetServerVersion - Update to SQL Server 2014 > Redeploy.