OpenSeesSP error

[amia]

Hi

I'm trying to run a 3D building model on OpenSeesSP, but it does not work when I use more than 1 processor. I run the model by sourcing multiple files. The error message occurs as soon as the Gravity Analysis .tcl is sourced.
Below is the error message:

"Zerolength:: sendSelf -- failed to send Materialid Slave Process Running 1
FEM_ObjectBrokerAllClasses::getNewUniaxialMaterial - 3
- no UniaxialMaterial type exists for class tag 18"

Judging from the error message, I thought a potential problem could be that the .tcl files are not created in a sequential order (also the model works if I use a single processor). So I allowed a pause between files (using the "after" command), and in each file at the end I put a "puts" command to see if the files were created (example of my run file is below) which they were in a sequential order.
Could you please let me know what may be causing the problem? (the system is set to Mumps).

Thank you
Anita

--------------------------------------------------------------------------------------------------------------------------------------------
# (ii) Run Analysis
source Tags.tcl
after 10000
source Materials.tcl
after 10000
source Sections.tcl
after 10000
source Nodes.tcl
after 10000
source InputAdditional.tcl
after 10000
source BackboneWall.tcl
after 10000
source BackboneJointExteriorHogPos.tcl
after 10000
source BackboneJointExteriorHogNeg.tcl
after 10000
source BackboneJointExteriorRoofHogPos.tcl
after 10000
source BackboneJointExteriorRoofHogNeg.tcl
after 10000
source BackboneJointInterior.tcl
after 10000
source BackboneJointInteriorRoof.tcl
after 10000
source BackboneJointInteriorWalls.tcl
after 10000
source BackboneJointInteriorWallsRoof.tcl
after 10000
source BackboneBeam.tcl
after 10000
source BackboneColumn.tcl
after 10000
source ElementConnectivity.tcl
after 10000
source ElementConnectivityJoints.tcl
after 10000
source ElementConnectivityBmCol.tcl
after 10000
source Constraints.tcl
after 10000
source Restraints.tcl
after 10000
puts " >>>> Model built <<<< "

# Recorders
source RecordersColMomRot.tcl
after 10000
source RecordersBmMomRot.tcl
after 10000
source RecordersJointsMomRot.tcl
after 10000
source RecordersWalls.tcl
after 10000
puts " >>>> Recorders sourced <<<< "

after 10000
# Analysis
source AnalysisGravity.tcl
#source AnalysisMonoPOforceXdir.tcl

[fmk]

what material is the truss using?