What operating system are you using?
Do you know which update you performed?
Did you download the update or was it on a disk?
Let us know
Could you restart your Mac and immediately hold down the SHIFT key when you hear the chime.
Hold it until you see the rotating gear below the grey Apple on the startup screen.
Release it and the computer should eventually take you to the Safe Boot login screen , although it may take up to 30 minutes.
Login like normal and then once all the way up reboot like normal.
Let me know what happens.
Click the Restart button located at the bottom of the login window and let the computer restart normally.
Let me know if the assistant shows up.
Perform the restart into Safe Boot and dont log in, Instead click the restart button and let it reboot like normal.
If it works you may see some updates flashing by however it should come up to the normal login box, In which case log in like normal.
Let me know what hapens.
If it seems it has hung up leave it to run so it can install the updates cleanly.
Let me know when you can log in.
Glad to hear it worked for you.
I will let the Admin group know you need some assistance wth paypal.
Thanks for using Jstanswer.com and let us know if we can help in the future
They will send you a message/email and take care of any problems you may have so feel free to shut down and call it a night.