SCCM 2012 Export Task Sequence fails with generic error message

Question

We have a complex task sequence comprising of more than 50 applications\packages, 1975 drivers, 18 driver packages etc etc. Its long, it's big and it will not export with it's content.
We have several environments for development test and live. I am attempting to export the primary task sequence with all it's dependencies from live so that I can port it over to a new development environment.
I can export the zip file without content and it comes to 92Mb in size. The entire task sequence software set is 50Gb+. When I attempt to export with all dependencies and content the process gets about 60% of the way through and fails with the error
"Error: The filename, directory name, or volume label syntax is incorrect"
Googling the error roughly defines the problem as 'the export process cannot access the defined source path for one of the dependant items'
I wrote a PowerShell script that looks as every application, package, driver, driver package, boot image, os image and software update package in the entire SCCM software library and verifies that each and every package has a valid UNC source directory
that can be reached using test-path.
I also wrote another tool that parsed the entire source software library on the server looking for permissions errors (permissions on the structure set at a directory level rather than inherited), directories that were too long, inaccessible or otherwise
blocked, nothing was found.
It will take a very long time to go through and check each and every dependency by hand - time I do not have at present.
I looked in the TaskSequenceProvider.log as that is supposed to contain messages from the export process and found the messages in there far too high a level to use
=======================
<![LOG[Setting status complete:  status code = 0x0; ]LOG]!><time="13:00:41.161-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="4168" file="exterror.cpp:128">
<![LOG[[PID: 3500] Invoking method SMS_TaskSequence.ExportXml]LOG]!><time="13:00:42.339-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="4168" file="wmiprovider.cpp:333">
<![LOG[[PID: 3500] Done with method SMS_TaskSequence.ExportXml]LOG]!><time="13:00:42.341-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="4168" file="wmiprovider.cpp:352">
<![LOG[Setting status complete:  status code = 0x0; ]LOG]!><time="13:00:42.341-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="4168" file="exterror.cpp:128">
<![LOG[[1AFF658 PID:3500] Received shutdown request from WMI]LOG]!><time="13:01:36.036-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="5592" file="wmiprovider.cpp:399">
<![LOG[[1AFF658 PID:3500] Initializing provider for namespace root\sms\site_P01]LOG]!><time="13:02:36.550-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068"
file="wmiprovider.cpp:90">
<![LOG[[1AFF658  PID:3500] Initialization of provider for namespace root\sms\site_P01 succeeded]LOG]!><time="13:02:36.551-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1"
thread="7068" file="wmiprovider.cpp:107">
<![LOG[[PID: 3500] Invoking method SMS_TaskSequence.LoadFromXml]LOG]!><time="13:02:36.554-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="wmiprovider.cpp:333">
<![LOG[[PID: 3500] Done with method SMS_TaskSequence.LoadFromXml]LOG]!><time="13:02:36.558-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="wmiprovider.cpp:352">
<![LOG[Setting status complete:  status code = 0x0; ]LOG]!><time="13:02:36.559-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="exterror.cpp:128">
<![LOG[[PID: 3500] Invoking method SMS_TaskSequence.ExportXml]LOG]!><time="13:03:05.428-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="wmiprovider.cpp:333">
<![LOG[[PID: 3500] Done with method SMS_TaskSequence.ExportXml]LOG]!><time="13:03:05.431-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="wmiprovider.cpp:352">
<![LOG[Setting status complete:  status code = 0x0; ]LOG]!><time="13:03:05.431-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="exterror.cpp:128">
<![LOG[[1AFF658 PID:3500] Received shutdown request from WMI]LOG]!><time="13:03:36.369-60" date="08-26-2014" component="TaskSequenceProvider" context="" type="1" thread="7068" file="wmiprovider.cpp:399">
====================
Is there any way of increasing the log verbosity? I need to see what item is causing the export to fail.
Is there another log containing the information about the export & what it is doing?
All out builds that use the task sequence complete successfully, we can edit the sequence fine, make changes etc. so no internal corruption we can find.
Any ideas?

Answer 1

Torsten, smsprov.log did indeed prove useful, I could see every package as it was validated. Unfortunately the log was wrapping about every 4 minutes and it takes 3+ hours for the task sequence to reach the fail point so I still cannot see the offending
package as it wraps before I can get to the log.
I will increase the size of the log and see if I can maintain some details to investigate.
There was nothing of note in the event logs, certainly nothing leading me to suspect that WMI might be reaching its limits.
I will keep looking for the cause and will post here when I find it <= positive thinking :)