When I launch the allegro constraints manager from concept HDL.
The whole spreadsheet was 'read only' state, as shown in the screenshot below,whatever the' physical' or spacing tab.
It looks like a software which was not activated.
How can I activate it,so as to make it works as usual.
Looks like you have back-annotated the constraints from Allegro PCB To Allegro Design Entry HDL. In order to be able to specify Physical/Spacing constraints in the schematic, you need the following directive added to the site.cpm file, if you have site.cpm file. If you don't then you *may* (don't know for sure) also modify the cds.cpm file in the install_dir to include this directive...
the issue has solved in the light of your solution.