Cause

The "Grid" page property value of the named page differs from the "Grid for page type" project setting. For instance, a grid of 4 mm was set for all electrical engineering schematic pages in your project ("Schematic multi-line" and "Schematic single-line"). But for the before mentioned schematic page, the "Grid" page property value was changed to 2 mm after the fact.  

Solution

Adapt the value of the "Grid" page property for the named page to the "Grid for page type" project setting, or vice versa.

(Call up the Grid page property by selecting the page navigator and clicking Popup menu > Properties. You will find the Grid for page type project setting by selecting the menu items Options > Settings, and opening the folders / subfolders Projects > "Project name" > Management in the tree view of the Settings <...> dialog, and clicking the Pages settings section.)

Then start a new check run.