Depends
For me it usually means I've either not pushed the switch hard enough, or not adjusted the contacts right (not got the same mech as you but in general)
As long as all other general safeties have been checked ( ie - protruding 510 positive for hybrids, no damage to your battery wraps, build is safe and not shorting) then its probably a bad connection either in the form of the switch not making a solid connection or some tarnish/arc spots (black spots where connection is made, all mechs can get it especially if you build low - those spots also have terrible conductivity - clean with a fine nail file)