While creating or updating any content in node add page I started getting the below error

The Page title is using the following invalid tokens: [node:title], [current-page:pager], [site:name].

• The Description is using the following invalid tokens: [node:summary].
• The Title is using the following invalid tokens: [node:title].
• The Description is using the following invalid tokens: [node:summary].
• The Content title is using the following invalid tokens: [node:title].
• The Content description is using the following invalid tokens: [node:summary].
• The Content modification date & time is using the following invalid tokens: [node:changed:custom:c].

It was working fine earlier but some recent code changes seemed to have caused this issue, on further debugging I found that one of the constants in define() was defined twice in the custom module.

Fixed the issue by removing duplicate entry and clearing cache. Token issues was fixed and I was able to save my nodes sucessfully.

Previous code

define('MY_CONSTANT', 'article');

define('MY_CONSTANT', 'article');

Corrected code

define('MY_CONSTANT', 'article');

Hope this helps !