c# - Intermittent errors while de-serializing object from XML -

i have program takes objects stored xml in database (basicly message queue) , de-serializes them. intermittently, 1 of following errors:

system.runtime.interopservices.externalexception: cannot execute program. command being executed "c:\windows\microsoft.net\framework\v2.0.50727\csc.exe" /noconfig /fullpaths @"c:\documents , settings\useraccount\local settings\temp\lh21vp3m.cmdline".    @ system.codedom.compiler.executor.execwaitwithcaptureunimpersonated(safeusertokenhandle usertoken, string cmd, string currentdir, tempfilecollection tempfiles, string& outputname, string& errorname, string truecmdline)    @ system.codedom.compiler.executor.execwaitwithcapture(safeusertokenhandle usertoken, string cmd, string currentdir, tempfilecollection tempfiles, string& outputname, string& errorname, string truecmdline)    @ microsoft.csharp.csharpcodegenerator.compile(compilerparameters options, string compilerdirectory, string compilerexe, string arguments, string& outputfile, int32& nativereturnvalue, string trueargs)    @ microsoft.csharp.csharpcodegenerator.fromfilebatch(compilerparameters options, string[] filenames)    @ microsoft.csharp.csharpcodegenerator.fromsourcebatch(compilerparameters options, string[] sources)    @ microsoft.csharp.csharpcodegenerator.system.codedom.compiler.icodecompiler.compileassemblyfromsourcebatch(compilerparameters options, string[] sources)    @ system.codedom.compiler.codedomprovider.compileassemblyfromsource(compilerparameters options, string[] sources)    @ system.xml.serialization.compiler.compile(assembly parent, string ns, xmlserializercompilerparameters xmlparameters, evidence evidence)    @ system.xml.serialization.tempassembly.generateassembly(xmlmapping[] xmlmappings, type[] types, string defaultnamespace, evidence evidence, xmlserializercompilerparameters parameters, assembly assembly, hashtable assemblies)    @ system.xml.serialization.tempassembly..ctor(xmlmapping[] xmlmappings, type[] types, string defaultnamespace, string location, evidence evidence)    @ system.xml.serialization.xmlserializer.generatetempassembly(xmlmapping xmlmapping, type type, string defaultnamespace)    @ system.xml.serialization.xmlserializer..ctor(type type, string defaultnamespace)    @ system.xml.serialization.xmlserializer..ctor(type type)    ..... 

or i'll one:

system.invalidoperationexception: unable generate temporary class (result=1). error cs0016: not write output file 'c:\documents , settings\useraccount\local settings\temp\nciktsd7.dll' -- 'could not execute cvtres.exe.'     @ system.xml.serialization.compiler.compile(assembly parent, string ns, xmlserializercompilerparameters xmlparameters, evidence evidence)    @ system.xml.serialization.tempassembly.generateassembly(xmlmapping[] xmlmappings, type[] types, string defaultnamespace, evidence evidence, xmlserializercompilerparameters parameters, assembly assembly, hashtable assemblies)    @ system.xml.serialization.tempassembly..ctor(xmlmapping[] xmlmappings, type[] types, string defaultnamespace, string location, evidence evidence)    @ system.xml.serialization.xmlserializer.generatetempassembly(xmlmapping xmlmapping, type type, string defaultnamespace)    @ system.xml.serialization.xmlserializer..ctor(type type, string defaultnamespace)    @ system.xml.serialization.xmlserializer..ctor(type type)    .... 

the program process thousands of messages day successfully, these errors maybe 2 or 3 times day. don't appear correlated specific kind of message, random.

any idea causes errors , how fix it?

eta - here's code causing errors, in case helps:

public class messagecontextbuilder<t> t : messagecontextbase  {     private static idictionary<string, xmlserializer> serializercache { get; set; }     public ilog logger { get; set; }       public messagecontextbuilder() {         if (serializercache == null) serializercache = new dictionary<string, xmlserializer>();         logger = logcontextmanager.context.getlogger<messagecontextbuilder<t>>();     }      public t buildcontextfrommessage(iemailqueuemessage msg) {         xmlserializer serializer = getserializer(typeof(t));         xmlreader r = xmlreader.create(new stringreader(msg.messagedetails));         if (serializer.candeserialize(r)) {             t rval = (t)serializer.deserialize(r);             rval.emailaddress = msg.emailaddress;             rval.localeid = msg.localeid;             rval.storeid = msg.storeid;             rval.messageid = msg.uniquekey;             return rval;         } else {             throw new argumentexception("cannot deserialize xml in message details message #" + msg.uniquekey);         }     }      public xmlserializer getserializer(type t) {         if (!serializercache.containskey(t.fullname)) {             serializercache.add(t.fullname, new xmlserializer(t)); // error occurs here, in xmlserializer constructor, intermittently         }         return serializercache[t.fullname];     } } 

you can pre-create serializers: http://msdn.microsoft.com/en-us/library/bk3w6240%28v=vs.100%29.aspx give try. next canonical candidate such problems virus scanner. tool writing disc while creating serializers. have seen virus scanner producing kind of strange errors in such situations.