I have tried to update my Joomla website,to the newest update from the admin area. After attempting to update,i have received this error message:
ERROR: Could not open archive part file root/temp/Joomla_3.8.2-Stable-Update_Package.zip for reading. Check that the file exists, is readable by the web server and is not in a directory made out of reach by chroot, open_basedir restrictions or any other restriction put in place by your host.
Seems you have permission issues on your root/temp directory. Make sure that the web server is able to read and write to that folder; make sure that permissions on that folder and ownership of that folder are both correct.
I am also had same problem in localhost while updating. I am just changed the path of tmp folder in joomla global configration.
Resolution
Login to Joomla Back office of the website;
Go to System > Global Configuration > Server tab;
Insert the absolute path for Temp directory of a website to Path to Temp Folder field.
e.g. D:\wamp\www\XXX_Site\tmp
