# NDSolve error with manipulate for 2 coupled ODEs

While trying to solve a system of coupled ODEs (for EVE[t] and FTZ[t]) with Manipulate, I keep getting a tremendous amount of errors, but I can't figure out why... among them, I get "NDSolve::ndnum: Encountered non-numerical value for a derivative at t == 0.", "ReplaceAll::reps: (...) is neither a list of replacement rules nor a valid dispatch table, and so cannot be used for replacing." and "NDSolve::dsvar: 0.004085714285714286 cannot be used as a variable.".

I don't understand why I get these errors since the time range I have seems to be reasonable, just as the initial conditions.

> (*** Initial conditions + free parameters ***)
tMax = 200;
eve0 = 2.0;
EVE0 = 2.0;
ftz0 = 2.0;
FTZ0 = 2.0;
d0 = 0.009; d1 = 2; d2 = 1; d3 = 4; d4 = 2; d5 = 4.0; d6 = 2.0; d7 = \
2.0; d8 = 2.0;
(*Solving the system*)
Clear[sol2]
Manipulate[
sol2 = NDSolve[{
Derivative[EVE][t] ==
d7 + E^(-t Subscript[k,
3]) (-d0 + d0 E^(t Subscript[k, 3]) +
eve0 Subscript[k, 3]) - (d3 EVE[t] Subscript[k, 13])/(
d4 + FTZ[t] Subscript[k, 4] + EVE[t] Subscript[k, 13]) - (
d5 EVE[t] Subscript[k, 1])/(
d6 + EVE[t] Subscript[k, 1] + FTZ[t] Subscript[k, 15]),
Derivative[FTZ][t] ==
d8 + (E^(-d1 t) (-d2 + d2 E^(d1 t) + d1 ftz0) Subscript[k, 6])/
d1 - (d3 FTZ[t] Subscript[k, 4])/(
d4 + FTZ[t] Subscript[k, 4] + EVE[t] Subscript[k, 13]) - (
d5 FTZ[t] Subscript[k, 15])/(
d6 + EVE[t] Subscript[k, 1] + FTZ[t] Subscript[k, 15]),
EVE == EVE0, FTZ == FTZ0}, {EVE, FTZ}, {t, 0, tMax},
MaxSteps -> Infinity];

Plot[{EVE[t], FTZ[t]} /. sol2, {t, 0, tMax}, PlotRange -> Full,
PlotStyle -> {Black}],
{{k3, 0.01}, 0.00, 1.00}, {{k13, 0.01}, 0.00, 1.00}, {{k15, 0.01},
0.00, 1.00}, {{k4, 0.01}, 0.00, 1.00}, {{k1, 0.01}, 0.00,
1.00}, {{k6, 0.01}, 0.00, 1.00}]


Remove the Subscripts!!!
Manipulate[sol2 = NDSolve[{Derivative[EVE][t] == d7 + E^(-t k3) (-d0 + d0 E^(t k3) + eve0 k3) - (d3 EVE[t] k13)/(d4 + FTZ[t] k4 + EVE[t] k13) - (d5 EVE[t] k1)/(d6 + EVE[t] k1 + FTZ[t] k15), Derivative[FTZ][t] == d8 + (E^(-d1 t) (-d2 + d2 E^(d1 t) + d1 ftz0) k6)/d1 - (d3 FTZ[t] k4)/(d4 + FTZ[t] k4 + EVE[t] k13)- (d5 FTZ[t] k15)/(d6 + EVE[t] k1 + FTZ[t] k15), EVE == EVE0,FTZ == FTZ0}, {EVE, FTZ}, {t, 0, tMax}, MaxSteps -> Infinity]; 