My system is running RedHat 7.3 and I decided to update to the later version of PHP (4.2.1). My version of Apache is 1.3.23 (the latest RPM package that Redhat has) and was working okay prior to my fiddling around. When I try to start httpd I get this message:

Cannot load /etc/httpd/modules/libphp4.so into server: /etc/httpd/modules/libphp4.so: undefined symbol: apr_bucket_type_file

Now the file /etc/httpd/modules/libphp4.so does exist, that has been checked on.

Slightly unrelated to your exact error... but I have read many reports that PHP 4.2.1 is pretty unstable and has quite a few quirks and troubles in it. I would suggest just sticking with the stable 4.1.2 version for now until the 4.2x source is stabalized.

Just saying, this error you are having now, will be just one of many according to quite a few other php people I have seen gripe about 4.2.1.

Just a heads up is all.

Regarding your exact error ... it might be trying to run the old php still, because the install of the new php didnt put all the pieces in the right locations. Check your apache conf and find out where the new php installed all the 'new' pieces on the system.

Just to make sure nothing prior was left over I did a complete uninstall of PHP and then reinstalled it again but the same apr bucket error comes upa gain.