In this case, the Row widget doesn’t constrain the size of its children, nor
does the Column widget. Lacking constraints from its parent widget, the second
Text widget tries to be as wide as all the characters it needs to display. The
self-determined width of the Text widget then gets adopted by the Column which
clashes with the maximum amount of horizontal space its parent the Row widget
can provide.

How to fix it?

Well, you need to make sure the Column won’t attempt to be wider than it can
be. To achieve this, you need to constrain its width. One way to do it is to
wrap the Column in an Expanded widget:

its source
code
shows. To further understand how to use the

this Widget of the Week video
on the Flexible widget.

Further information:

The resources linked below provide further information about this error.

Flexible (Flutter Widget of the Week)