migration - Error migrating from GeneXus 9 to GeneXus Evo 2 U5 -

i'm migrating kb genexus 9 genexus evo 2 u5. i'm using .net , sql server, , followed steps mentioned in gxtechnical have following error:

========== developermenu compilation started ========== gxexec "c:\modelos gx\postulantes\dataprot\blddevelopermenu.cs" -r:gxbasebuilder.dll -arg:csc="c:\windows\microsoft.net\framework\v3.5\csc.exe" -arg:mdlpath="c:\modelos gx\postulantes\dataprot"  building bin\messages.spa.dll read in 570 resources 'messages.spa.txt' writing resource file...  done. compilador de microsoft (r) visual c# 2008, versi¢n 3.5.30729.5420 para microsoft (r) .net framework, versi¢n 3.5 (c) microsoft corporation. reservados todos los derechos. error:build error target bin\genexus.programs.common.dll: .\gxobjectcollection.cs not exist. developermenu compilation failed  ========== assemblies compilation started ========== gxexec "c:\modelos gx\postulantes\dataprot\bldassemblies.cs" -r:gxbasebuilder.dll -arg:csc="c:\windows\microsoft.net\framework\v3.5\csc.exe" /noconfig -arg:mdlpath="c:\modelos gx\postulantes\dataprot" error:build error target bin\genexus.programs.common.dll: .\gxobjectcollection.cs not exist. assemblies compilation failed rebuild failed 

what should solve problem?

try these steps:

1. in genexus, go tools -> explore knowledgebase directory
2. delete *.ari, *.0?? files
3. in genexus, go tools -> explore target environment directory
4. delete folder
5. in genexus, go build -> rebuild

if keep having same error, @ entire output; there may other errors before one. if not, contact genexus support team. if yes, search in google or search.genexus.com solutions of new errors.