This part of your model already has 4 error messages:
syntax error
context: set >>> j0:=0; <<<
syntax error
context: sum {a in >>> J, <<< b in T} (s[a] * x[a,b] + h[a] * I[a,b]);
syntax error
context: subject to Lager {a in >>> J, <<< b in T}:
syntax error
context: subject to Kapazität {a in >>> J, <<< b in T}:
The first one occurs because you are assigning a number to a set. If you need to define a set whose only member is the number 0, you should write:
set j0 := {0};
The other errors occur because you are writing a in J where J is a parameter. You need to say that a is in a set; in your case, a in j would be correct. Then you will find that there is the same problem with b in T, which you can correct similarly.
After these errors are fixed, you should find that AMPL goes on to read other “subject to” statements in your model.