Convert detail into an editable detail

Hi community, 



I have created a detail and now I wanted to convert the detail into an editable list. The option that is provided in the detail setup is disabled. Then I added the required code in the client module. The detail has been converted to editable list but when I click on the record it is throwing the following error. 

The details regarding the issue are attached below.

Could you let me know how can I convert an already existing detail to an editable one?





Thanks in advance

Goparna Nasina.