Worked for me for CEP:
mine (marked Invalid -- SIGH...):
https://secure.worldcommunitygrid.org/ms/devi...Log.do?resultId=156841413
<core_client_version>6.2.12</core_client_version>
<![CDATA[
<stderr_txt>
Calling gridPlatform.init()
Calling initGraphics()
INFO: No state to restore. Start from the beginning.
Calling gridPlatform.init()
Calling initGraphics()
Calling gridPlatform.init()
Calling initGraphics()
Calling gridPlatform.init()
Calling initGraphics()
Calling gridPlatform.init()
Calling initGraphics()
Calling gridPlatform.init()
Calling initGraphics()
called boinc_finish

</stderr_txt>
]]>

Wingman's (marked valid because the next guy's must have errored the same way):
https://secure.worldcommunitygrid.org/ms/devi...Log.do?resultId=156841412
<core_client_version>6.4.5</core_client_version>
<![CDATA[
<stderr_txt>
Calling gridPlatform.init()
Calling initGraphics()
INFO: No state to restore. Start from the beginning.
[ERROR] Failed to open either source or destination files while copying wcgrestart.rst to ../../projects/www.worldcommunitygrid.org/E000428_236A_002f2c00a_0_3. Error: 2
called boinc_finish

</stderr_txt>
]]>

BTW: I can verify that this is the same WU, since this particular one has the WU listed in the error line. My Wu was: E000428_ 236A_ 002f2c00a_ 1

I have tried this on HCC since that is a project that seems to be hung up waiting for results before it is valid. I copied the address bar from the separate window opened for the status link and placed it into a new tab. I was able to see some of what was happening. It started off with the following

<core_client_version>5.8.16</core_client_version>
<![CDATA[
<message>
Maximum disk usage exceeded
</message>
<stderr_txt>
00 C:\WINNT\system32\WS2_32.DLL (5.0.2195.6601) (-exported- Symbols Loaded)
File Version : 5.00.2195.6601
Company Name : Microsoft Corporation
Product Name : Microsoft(R) Windows (R) 2000 Operating System
Product Version: 5.00.2195.6601