I have created a new custom entity X this is mainly to be used as an intersection entity, a manual n:n relationship with the other two existing custom entities.
On one of the existing entity i am then adding a subgrid where i can add records using the quick create form for the new entity X, when i create a record using the subgrids + button i am getting the below error, however, it does create the record successfully. There is no javascript on the new entity but quite a few scripts on the parent entity existing entity where i have added the subgrid, i cannot change or remove any of these scripts as they are from our third party vendor.
How can i check what is causing this and get rid of the issue.
Thanks
PS