Hi,
CCleaner showed me this message:
-------------------------------------------------------------
Microsoft C++ Exception
CCleaner v3.18.1707 (64-bit)
MS Windows 7 Ultimate 64-bit SP1
Intel Core2 Solo CPU U3500 @ 1.40GHz
4,0GB RAM
Mobile Intel 4 Series Express Chipset Family
ID=-1
PR=0
DA=
RK=
RU=32
CK=0
SK=
VK=
VA=N_MOZ_HISTORY
CR=90
PF=0
EI=0
FL=103
IIT=0
FI=-1
SI=0
-------------------------------------------------------------
No crash or repeatabel! Maybe it depends on Windows Update... no other tasks in the taskbar.
This is usually caused by a mozilla product (not limited to this list: Firefox, Thunderbird, Seamonky, Songbird, older emusic mp3 downloader) still running in the background, so you should check your task manager (on the Processes tab) for any zombies (including plugincontainer.exe)
No crash or repeatabel!
I don't understand, are you saying this is not repeatable? not so sure it's worth reporting if this is the case.
I use Firefox and Thunderbird on my system. I cant't write if they are the problem or not, because I know the message "Firefox/Mozilla needs to be closed to..." ( I use the german language and the message is in english ;-) ) and this message wasn't in this moment. Yesterday, I installed some Microsoft Updates, but I cant' write if this was in the background while CCleaner worked.
After this error message CCleaner went normal to end of clean process. No crash and I tried some new starts or cleaning processes... OK.