CCleaner appcrash after selecting install. in CCleaner Bug Reporting Posted January 23, 2017 Windows 7 64 dell laptop. Downloaded and running from Windows Explorer. Trend AV. Also fails to install with AV disabled. Fails install in safe mode. Running install as administrator. Fails on downloaded versions from 5.23 - 5.26. appcrash ccsetup526.exe 188.8.131.52 pfUI.dll Your assistance is greatly appreciated.