diff --git a/dfm_tools/meshkernel_helpers.py b/dfm_tools/meshkernel_helpers.py
index 7c8b50d7..c95a630b 100644
--- a/dfm_tools/meshkernel_helpers.py
+++ b/dfm_tools/meshkernel_helpers.py
@@ -115,7 +115,7 @@ def meshkernel_delete_withgdf(mk:meshkernel.MeshKernel, coastlines_gdf:gpd.GeoDa
         xx = np.array(xx)
         yy = np.array(yy)
         
-        delete_pol_geom = meshkernel.GeometryList(x_coordinates=xx, y_coordinates=yy) #TODO: .copy()/to_numpy() makes the array contiguous in memory, which is necessary for meshkernel.mesh2d_delete()
+        delete_pol_geom = meshkernel.GeometryList(x_coordinates=xx, y_coordinates=yy)
         mk.mesh2d_delete(geometry_list=delete_pol_geom, 
                          delete_option=meshkernel.DeleteMeshOption.INSIDE_NOT_INTERSECTED,
                          invert_deletion=False)
diff --git a/dfm_tools/modelbuilder.py b/dfm_tools/modelbuilder.py
index f7975141..39f20ee2 100644
--- a/dfm_tools/modelbuilder.py
+++ b/dfm_tools/modelbuilder.py
@@ -260,7 +260,7 @@ def preprocess_merge_meteofiles_era5(
     
     # TODO: align with variables_dict from dfmt.download_ERA5()
     dict_varkey_quantities = {
-        'ssr':'solarradiation',
+        'ssr':'netsolarradiation',
         # 'sst':'sea_surface_temperature',
         'strd':'longwaveradiation',
         # 'slhf':'surface_latent_heat_flux',
@@ -280,6 +280,7 @@ def preprocess_merge_meteofiles_era5(
         'rhoao':'airdensity',
         }
     
+    
     for varkey in varkey_list:
         if isinstance(varkey, list):
             raise TypeError(
@@ -294,6 +295,14 @@ def preprocess_merge_meteofiles_era5(
                 "issue if you need this."
                 )
         
+        # TODO: remove this warning after a while, it was implemented in
+        # https://github.com/Deltares/dfm_tools/issues/1253
+        if varkey == "ssr":
+            logger.warning(
+                "you are using ssr/netsolarradiation, beware that this "
+                "quantity only exists in Delft3D-FM 2026.01 and above."
+                )
+        
         fn_match_pattern = f'era5_{varkey}_*.nc'
         file_nc = os.path.join(dir_data, fn_match_pattern)
         
diff --git a/dfm_tools/xarray_helpers.py b/dfm_tools/xarray_helpers.py
index 95c88eaa..4c776e2c 100644
--- a/dfm_tools/xarray_helpers.py
+++ b/dfm_tools/xarray_helpers.py
@@ -370,10 +370,6 @@ def get_unit(da):
         # 3600s/h #TODO: 1W = 1J/s, so does not make sense?
         ds[varkey_sel] = ds[varkey_sel] / 3600
         ds[varkey_sel].attrs['units'] = new_unit
-    #solar influx increase for beta=6% subtraction in DFM
-    if 'ssr' in varkeys:
-        print('ssr (solar influx) increase for beta=6% subtraction in DflowFM')
-        ds['ssr'] = ds['ssr'] / 0.94
     
     # restore attrs and encoding of data_vars
     for varkey in varkeys:
diff --git a/pyproject.toml b/pyproject.toml
index 31c3daa1..cd2b154b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -51,8 +51,8 @@ dependencies = [
 	"rws-ddlpy>=0.8.0",
 	#pooch>=1.1.0 has attribute retrieve
 	"pooch>=1.1.0",
-	#hydrolib-core>=0.9.9 removed obsolete keywords to avoid model crash with 2026.01
-	"hydrolib-core>=0.9.9",
+	#hydrolib-core>=0.10.0 added support for quantity netsolarradiation
+	"hydrolib-core>=0.10.0",
 	#meshkernel>=8.2.1 supports illegalcells via the face-node-connectivity
 	"meshkernel>=8.2.1",
 ]
diff --git a/tests/test_modelbuilder.py b/tests/test_modelbuilder.py
index b540f21d..b695bc70 100644
--- a/tests/test_modelbuilder.py
+++ b/tests/test_modelbuilder.py
@@ -13,6 +13,7 @@
 import xarray as xr
 import numpy as np
 from dfm_tools.modelbuilder import get_quantity_list, get_ncvarname
+import logging
 
 
 @pytest.mark.unittest
@@ -420,3 +421,31 @@ def test_preprocess_merge_meteofiles_era5_missing_files(tmp_path, ds_era5_empty)
                                                         dir_output=tmp_path,
                                                         time_slice=slice(date_min, date_max))
     assert "No files found for pattern" in str(e.value)
+
+
+@pytest.mark.unittest
+def test_preprocess_merge_meteofiles_era5_ssr_warning(tmp_path, ds_era5_empty, caplog):
+    """
+    this test is to make sure this code emits a warning about ssr
+    without caplog the code actually raises an error, which is not considered here.
+    this is due to the fact that we are trying to concatenate an empty dataset here
+    ValueError "Could not find any dimension coordinates to use to order the datasets for concatenation"
+    """
+    file_nc = os.path.join(tmp_path,"era5_ssr_empty.nc")
+    ds_era5_empty = ds_era5_empty.rename_vars(msl="ssr")
+    ds_era5_empty.to_netcdf(file_nc)
+    
+    ext_old = hcdfm.ExtOldModel()
+    date_min = ds_era5_empty.time.to_pandas().iloc[0]
+    date_max = ds_era5_empty.time.to_pandas().iloc[-1]
+    varlist_list = ['ssr']
+    # with pytest.raises(ValueError) as e:
+    with caplog.at_level(logging.WARNING):
+        ext_old = dfmt.preprocess_merge_meteofiles_era5(
+            ext_old=ext_old,
+            varkey_list=varlist_list,
+            dir_data=tmp_path,
+            dir_output=tmp_path,
+            time_slice=slice(date_min, date_max),
+            )
+    assert "you are using ssr/netsolarradiation, beware that this quantity only exists in Delft3D-FM 2026.01 and above" in caplog.text