What does the error "Use of undefined constant CRAFT_BUILD - assumed 'CRAFT_BUILD'?" mean?

Question

Accessing my /admin of a craft site and i get this error.

Internal Server Error

Use of undefined constant CRAFT_BUILD - assumed 'CRAFT_BUILD'

Never happened before today, I'm running PHP v5.6.30.

Thanks

Answer 1

Had a plugin installed which had been using CRAFT_BUILD and as its been deprecated it was throwing the error, problem was could access admin to update plugin.

Manually, entered CRAFT_BUILD and other deprecated info into craft/app/Info.php and it let me login to fix.

Answer 2

I ran into this error when updating a live Craft site. My local update had gone fine. So I ended up editing my craft/app/Info.php file (live) from:

define('CRAFT_VERSION', '2.6');
define('CRAFT_BUILD', '2949');

to just:

define('CRAFT_VERSION', '2.6.2949');

I then ran into the error:

Internal Server Error Use of undefined constant CRAFT_MIN_VERSION_REQUIRED

So again, I updated my craft/app/Info.php to add the line:

define('CRAFT_MIN_VERSION_REQUIRED', '2.1.2570');

It then logged me in and and asked me to finish updating SEOmatic, so I clicked Update and it was running fine again but showing the following depreciation errors:

craft()->getBuild() has been deprecated. As of Craft 2.6.2951, craft()->getVersion() returns the complete version number (X.Y.Z). /var/www/craft/app/etc/behaviors/AppBehavior.php (149)