Hi Koen,
The expression works on most cases but on some values it just returns NULLS when it ignores failures or the following errors that make the task fail.
[Derived Column [187]] Error: SSIS Error Code DTS_E_INDUCEDTRANSFORMFAILUREONERROR.
The "component "Derived Column" (187)" failed because error code 0xC0049063 occurred,
and the error row disposition on "output column "Derived Column 3" (250)"
specifies failure on error. An error occurred on the specified object of the specified component.
There may be error messages posted before this with more information about the failure.
[Derived Column [187]] Error: SSIS Error Code DTS_E_INDUCEDTRANSFORMFAILUREONERROR.
The "component "Derived Column" (187)" failed because error code 0xC0049063 occurred, and the error row disposition
on "output column "Derived Column 3" (250)" specifies failure on error.
An error occurred on the specified object of the specified component.
There may be error messages posted before this with more information about the failure.
[SSIS.Pipeline] Error: SSIS Error Code DTS_E_PROCESSINPUTFAILED.
The ProcessInput method on component "Derived Column" (187) failed
with error code 0xC0209029 while processing input "Derived Column Input" (188).
The identified component returned an error from the ProcessInput method. The error is specific
to the component, but the error is fatal and will cause the Data Flow task to stop running.
There may be error messages posted before this with more information about the failure.
[SSIS.Pipeline] Error: SSIS Error Code DTS_E_PROCESSINPUTFAILED.
The ProcessInput method on component "Derived Column" (187) failed with error code 0xC0209029
while processing input "Derived Column Input" (188). The identified component returned an error
from the ProcessInput method. The error is specific to the component, but the error is fatal
and will cause the Data Flow task to stop running. There may be error messages posted before this
with more information about the failure.
I'm uncertain on what could be wrong.