We're running Concrete 5.6.1. There are two blocks I'm having the same issue with. (ProEvents and Gallery from Concrete). Whenever I try to install either of them, I get the same general error:

Warning: require_once(/projects/work/sagora-website-dev/concrete/blocks/gallery/controller.php): failed to open stream: No such file or directory in /projects/work/sagora-website-dev/concrete/core/models/block_types.php on line 826 Fatal error: require_once(): Failed opening required '/projects/work/sagora-website-dev/concrete/blocks/gallery/controller.php' (include_path='/p/sagora-website-dev/libraries/3rdparty:/projects/work/sagora-website-dev/concrete/libraries/3rdparty:.:/usr/local/share/pear/share/pear') in /projects/work/sagora-website-dev/concrete/core/models/block_types.php on line 826

As you can see, for some reason Concrete is looking in the /concrete/blocks folder for the gallery block, instead of the package folder of the package it is in. Here is the basic code used in both packages to install the block:

$pkg = parent::install();
// install block
BlockType::installBlockTypeFromPackage('gallery', $pkg);

I'm not 100% sure these blocks are compatible with the newest version of Concrete, but thought I'd check and see if anyone has come across this.