NullPointerException when speckle filtering

I have an issue when applying speckle filtering (Lee refined) on Sentinel-1 data.
I am using SNAP 2.0 and SLC data (already splitted/orbit corrected/calibrated and debursted).
When running the speckle filter I have this error message:
“A problem occurred during processing the target product processing.
Type: OperatorException
Messge: Speckle-Filter: java.lang.NullPointerException”
Any help would be appreciated.

Most speckle filters only work on detected (non-complex) data. You should run “S-1 SLC to GRD” before applying speckle filtering.

ps. @lveci I think the speckle-filters should issue an informative error when the user tries to apply them on an incorrect product type.

It works when using Radar/Polarimetric/polarimetric Speckle filter process.
What is the difference with the Radar/Speckle filtering/Single product speckle filter process ?

The Radar/Polarimetric/polarimetric Speckle filter are designed to work also on SLC products (full polarimetric and covariance or coherency matrix), while the “Speckle Filtering” option under RADAR are dedicated to detected products.

ok, got it!
Thank you for your replies.