Bug 369626

If you open Settings/Configure digiKam/Templates you get an empty template and you can  edit the fields in all four tabs. But if you leave the fields in the "Subjects" tab unedited and save the template to the template list you are not longer able to edit the "Subjects" fields. 

Reproducible: Always

Steps to Reproduce:
1. Open Settings/Configure digiKam/Templates
2. Fill in a field, e.g. Author Names
3. Fill in the "Template Title" field and click "Add"

Actual Results:  
If you go now to the "Subjects" tab you will find everything dimmed/greyed out, i.e. not accessible.

Expected Results:  
The "Subjects" data should still be editable.

The same happens of course if you have already a list of templates and among them some without "Subjects" data and you want to add those data later. But also when you have an image without "Subjects" data selected and access the Tempplate Manager by clicking the little edit button beside the "Template:" field in the "Information" tab of the "Caption" section of the Right Sidebar the "Subjects" tab will be dimmed provided the image contains already data in one of the other tabs.
Once there are some "Subjects" data stored with the template everything works as one would expect, i.e. you are able to edit these data.