This should certainly not happen under normal circumstances. Two possible causes:
- You upgraded MultiChain – some later versions check more things in the parameter set than earlier versions, for example that the total quantity to be issued of the chain's native asset won't cause an integer overflow.
- You accidentally modified the parameter set file in params.dat, or overwrote it.
If neither of these explanations makes sense, please post the params.dat file for this chain here, and we can see what might be causing the problem.