Have you asked the addon developer?

No. It was an upgrade to concrete 5, not an add-on

Whilst it was an upgrade to c5, it is an addon giving the error message. Hence you should ask the addon developer to find out if there are any upgrade or compatibility related issues for that addon.

Got an error like the one above. Can't think of a third party addon causing the error.
Where should I look?
[error]
Warning:
require_once(/home/dtbweb1q/public_html/updates/concrete5.6.2.1_updater/concrete/blocks/mededelingen/controller.php)
[function.require-once]: failed to open stream: No such file or directory
in
/home/dtbweb1q/public_html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php
on line 218

Fatal error: require_once() [function.require]: Failed opening required
'/home/dtbweb1q/public_html/updates/concrete5.6.2.1_updater/concrete/blocks/mededelingen/controller.php'
(include_path='/home/dtbweb1q/public_html/libraries/3rdparty:/home/dtbweb1q/public_html/updates/concrete5.6.2.1_updater/concrete/libraries/3rdparty:.:/usr/lib/php:/usr/local/lib/php')
in
/home/dtbweb1q/public_html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php
on line 218
[/error]

Solved:
In my case it was a rogueblocktype called 'mededelingen'.
Looked at the database (phpMyAdmin) and there was a BlockTypes called mededelingen. Did a database backup. Removed the blocktype mededelingen from the database, now everything seems to work.

Thanks. My mistake

I'm experiencing the exact same error after uploading and attempting to install a package:

Warning: require_once(/updates/concrete5.6.2.1_updater/concrete/blocks/enlil_likes_this2/controller.php): failed to open stream: No such file or directory in /updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 218 Fatal error: require_once(): Failed opening required '/updates/concrete5.6.2.1_updater/concrete/blocks/enlil_likes_this2/controller.php' (include_path='/libraries/3rdparty:/updates/concrete5.6.2.1_updater/concrete/libraries/3rdparty:.:/usr/lib/php:/usr/local/lib/php') in /updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 218

All the class names and handles in the package controllers were set like EnlilLikesThis2 and enlil_likes_this_2. You will notice above c5 is looking for this: "/enlil_likes_this2"

I've gone back and made another package that mimics this one naming everything without the 2 and the package installs just fine. Is there something screwy with using a single number in a handle maybe ?? either way at the moment I'm stuck with the package unable to install and my block types page is broken.

Why is it looking in the updates folder for the block controller in the first place?? Any Ideas ??

solved my issue by following mhawk's "removing packages gone wild" post here:

http://www.concrete5.org/community/forums/installation/unable-to-un...

Note: I removed the package entry from the packages table in the database as well!!

Its looking *last* for a core block of that name. Having failed to find it anywhere else - override, package etc, c5 decides it is probably a core block and tries to load it from the core blocks directory.

As to why it failed to find it, I regularly get the same glitch because I have messed up on file naming, capitalisation, correct package handle ........ Then I find my trivial typo and everything works OK.

I searched for about an hour and a half trying to find the error and was completely stumped. I dumped it and continued with the alternate package that was working!

I had the exact same error message. I'd just created my first custom block (yeah, still learning!).

I looked at the link for "packages gone wild" and checked my BlockTypes table - but there was no sign of my new block. I went back to the editor I'm using - phpStorm - to look at the controller.php. I'd used New-PHP Class to create the file, and it had added a line for a namespace. I took out that line, and presto-magico, it works now.

Thought I'd share just in case someone else gets stumped by this.

The error was that the developer could not add a block. when we tried the to that we got this error:

PHP Warning: equire_once(/var/www/html/packages/login/blocks/login/controller.php): failed to open stream: No such file or
directory in /var/www/html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 217,
PHP Fatal error: require_once(): Failed opening required '/var/www/html/packages/login/blocks/login/controller.php' (include_path='/var/www/html/libraries/3rdparty:/var/www/html/updates/concrete5.6.2.1_updater/concrete/libraries/3rdparty:.:/usr/share/pear:/usr/share/php') in /var/www/html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 217,

I followed the tips that were given in this thread.
And after deleting the row in the table BLOCK_TYPE I got the it working agian.

I'm not an expert on this but the row I had to delete looked pretty mandatory. here is a part of the row:

30 login Login Box Lets you add a login box as a block.

So before I tell the lovely lady in despair that all is fine again, could someone tell what this is for and if I didn't brake it even more?

Thanks.