Start menu item default value issues ?

In a Start menu asset type Page, type  New.

1- Multiple valued attributes of type Asset couldn't hold more than one asset in the default value/

2-  Miss grouped attributes and default values in the start menu as in the below image.

3-  On creating an asset using them menu, the below error (see attached log as well ) and exception happen, the default values are:(dimension, template, singe valued flex asset, single valued flex asset, String, String, Recommendation).

The assets used as default values were used to create a page using the default Page asset start menu and they are all working fine.