Hello,
I’ve been having a hard time with interfaces in ATENA 2025 Engineering.
In the model I assigned two Interface 3Ds between solids, and the analysis runs. However when I try to inactivate one of these through the ‘ Construction process’ option in the ‘Task’ input window, I get the following error:
‘Writing construction process "interface_mono" ended with an error due to unknown GROUP ID.’
(The other interface presist throught every construction stage so I did not include that in the tables, and I do not get the error message regading that)
I have checked the INP file and it suggests that there is actually two group ids assigned:

ELEMENT TYPE ID 131 NAME "Interface 3D wedge" TYPE "CCIsoGap<xxxxxx>"  LINEAR
ELEMENT TYPE ID 132 NAME "Interface 3D quad"  TYPE "CCIsoGap<xxxxxxxx>"  LINEAR

ELEMENT GROUP ID 120001 NAME "interface_mono 3D wedge" TYPE 121 MATERIAL 85 GEOMETRY 12000 ;
ELEMENT GROUP ID 120002 NAME "interface_mono 3D quad" TYPE 122 MATERIAL 85 GEOMETRY 12000 ;

In case of other elements it looks the following:

ELEMENT TYPE ID 71 NAME "BE #7 Tetra Plate"  TYPE "CCIsoTetra<xxxx>"      LINEAR ;
ELEMENT TYPE ID 72 NAME "BE #7 Pyram. Plate" TYPE "CCIsoBrick<xxxxxxxx>"  LINEAR ;
ELEMENT TYPE ID 73 NAME "BE #7 Wedge Plate"  TYPE "CCIsoWedge<xxxxxx>"    LINEAR ;
ELEMENT TYPE ID 74 NAME "BE #7 Hexa Plate"   TYPE "CCIsoBrick<xxxxxxxx>"  LINEAR ;

ELEMENT GROUP ID 70001 NAME "Plate" TYPE 71 MATERIAL 75 GEOMETRY 7000 ;
ELEMENT GROUP ID 70002 NAME "Plate" TYPE 72 MATERIAL 75 GEOMETRY 7000 ;
ELEMENT GROUP ID 70003 NAME "Plate" TYPE 73 MATERIAL 75 GEOMETRY 7000 ;
ELEMENT GROUP ID 70004 NAME "Plate" TYPE 74 MATERIAL 75 GEOMETRY 7000 ;

It would be important to remove it in certain intervals because if I exclude it from the construction process table the analysis crashes(it basically floats between the assigned solids), but I cannot start the analysis by deactivating it due to the INP error.
I was wondering if there is a way to either cut down to one group ID or are there any alternative solutions to this type of error, maybe I skipped a crucial step when assigning the interface or creating the mesh, since it might be a mesh incompatibility problem.
I have also tried to run the ‘interface3D with shear’ tutorial (available under the ‘Tutorials’ in ATENA center) by inactivating the interface in interval one, but I get the same error message.
It is also worth mentioning that the analysis runs when I delete the interface from the model and it behaves as expected under loads and according to the set construction process.

Thank you in advance for your advice