Issue
Connections between Menta function blocks not been allowed
Environment
Menta
Cause
If the rectangle (Dotted line) covers the pixel of the connection point of any function block / output, this stops the mouse from selecting the input connector to allow the connection to be made.
This also occurs if you use any of the Comment, Line or Rectangle Menta features and overlay these too closely to the connection point.
Resolution
Select the rectangle (dotted line), (or overlaying object) and move it away from the connection point as shown below.