Bounds Error in Neural Network Training Process

[CatYukino]

Hi. I'm using Optim.jl to train a neural ODE, while it always appears some bounds errors like:

ERROR: BoundsError: attempt to access 13-element Vector{Float64} at index [1:200]

I checked the code and found that it appeared when I used BFGS and LBFGS. I firstly used ADAM and it worked well, while it converges slowly, which means the time cost is too large... So I chose (L)BFGS and some other second order algorithms, while the boundserror always occurred. I wonder if the design of the model is too complex(in fact there is warning that the problem is stiff), or is there any other choices to solve the problem?

Thanks!