Did this behavior start suddenly? Or does it behave like this from the beginning? (I.e. was it e.g. working properly yesterday?)

Yestarday ADNM works fine.
This morning we installed another program with a db that works under MSDE, without modify any setting in MSDE.
In the last login in ADNM, I think I accidentaly remove sa password under File/Settings/SQL … but I’not sure.

Now the sa password is empty.