Hello StackOverflow!

We deploy our application using ClickOnce, installed from a file path. For 24 versions it has been working perfectly - now, on version 25 I get the following error once the application has installed and it launches:

If I test a previous deployment on the same machine, it works.

Where can I even begin to look to find the cause of this error? I already checked the windows event logs - nothing.

EDIT: I noticed that while the dialog is displayed, a temporary xml file 'WER561D.tmp.WERInternalMetadata.xml' is generated in my temp folder. Here is the contents (it might contain clues helpful to those more knowledgeable in this area than I):

<?xml version="1.0" encoding="UTF-16"?>
<WERReportMetadata>
    <OSVersionInformation>
        <WindowsNTVersion>6.1</WindowsNTVersion>
        <Build>7600 </Build>
        <Product>(0x4): Windows 7 Enterprise</Product>
        <Edition>Enterprise</Edition>
        <BuildString>7600.16385.x86fre.win7_rtm.090713-1255</BuildString>
        <Revision>1</Revision>
        <Flavor>Multiprocessor Free</Flavor>
        <Architecture>X86</Architecture>
        <LCID>1033</LCID>
    </OSVersionInformation>
    <ProblemSignatures>
        <EventType>CLR20r3</EventType>
        <Parameter0>applaunch.exe</Parameter0>
        <Parameter1>2.0.50727.4927</Parameter1>
        <Parameter2>4a275abe</Parameter2>
        <Parameter3>mscorlib</Parameter3>
        <Parameter4>2.0.0.0</Parameter4>
        <Parameter5>4a275af7</Parameter5>
        <Parameter6>4f3</Parameter6>
        <Parameter7>0</Parameter7>
        <Parameter8>System.Security.Security</Parameter8>
    </ProblemSignatures>
    <DynamicSignatures>
        <Parameter1>6.1.7600.2.0.0.256.4</Parameter1>
        <Parameter2>1033</Parameter2>
    </DynamicSignatures>
    <SystemInformation>
      -- removed for privacy reasons --
    </SystemInformation>
</WERReportMetadata>

Another key point is that I am publishing via Visual Studio, there is no manual manifest editing going on.