Before following the steps make sure you have four digit I cloud verification code , all web mail , I cloud id , Apple ID & their password respectively and wireless network password in your records .
Click on go to go folder & type ~/Library go to folder keychains & select ( can use command + A ) alfa numeric folder , loginkeychain -db , meta data .keychain -db & delete ( command + delete ) to the trash . Restart & empty the trash .
A pop - up appears on the desktop this Mac can’t connect to I cloud because of a problem with ……web mail is written open I cloud preferences to fix this problem
( a ) later ( b ) I cloud preferences , so click on I cloud preferences .
Go to system preferences click on google mail , contacts & 3 more it prompts to enter web mail password , click on next .
Then click on I cloud , I cloud drive & 8 more on the right side check the box of key chain , an pop -up appears enter your Apple ID password & set up I cloud keychain .
Password ….required enter the password in the empty field ( a ) cancel ( b ) ok , click on ok
An pop up appears to set up I cloud keychain on this Mac request approval from one of your other devices using I cloud keychain .if no other devices are available , use I cloud security code ( a ) use code ( b ) cancel ( c ) request approval so , click on use code .
Enter your four digit I cloud security code & click on next enter the verification code ( 6 numbered ) sent to the mobile .
Open airport utility via spotlight & click on base station & enter the wireless network password
( a ) remember this password in my keychain ( cancel , ok) so click on ok .
Open safari & set the home page once again .
Note : We have emptied all contents of keychain into the trash , as keychain was corrupted restarted the system & emptied the trash , & various pop - up appears and even after entering the passwords , the pop - up never goes away .So follow the above steps and the pop will vanish , but in the method I CLOUD FOUR DIGIT VERIFICATION CODE HAS A MAJOR ROLE .