So I have an ultra realistic version of 1.3.1 KSP with 61 mods installed, including RSS, Ven's Part Revamp and RealFuels but not RO. I built a Mars lander with a Terrier engine in the Aerozine50-NTO configuration and found out the engine was being repelled from the planet because, when I scaled it down, the mass went from 0.2 tons to -0.115 tons, and so the engine floats away. It also happens with other parts such as some nuclear engines which go as low as 4 tons negative mass. I don't know how to fix this. The original file for the Terrier did nothing when I tried to change its mass, nor did the Ven's Part Revamp one and I'm too scared to touch the TweakScale one. Is there anything I can do to fix this? This is my list of mods. Any help is appreciated!
000_AT_Utils - 1.5 USI Tools - 0.10.2
ToolbarControl - 0.1.4.7
Ablative-Airbrake - 0.3
AlmostFreeLaunchClamps - 0.2.2
B9 Animation Modules - 1.1
B9 Part Switch - 2.1.1
B9 Aerospace HX Parts - 6.4
CameraTools - 1.9
CCTV - 1.1.2
Chatterer Extended - 0.6.2
Chatterer - 0.9.93.1804
CollisionFX - 4.0
Community Category Kit - 2.0.2
Community Resource Pack - 0.8.1
CommunityTechTree - 3.2.1
CryoEngines - 0.5.11
CryoTanks - 0.4.9
Deadly Reentry - 7.6.2
DynamicBatteryStorage - 1.2
FASA Launch Clamps - 1.1.4
Ferram Aerospace Research - 0.15.9.1
Firespitter - 7.6
FMRS (Flight Manager For Reusable Stages) - 1.2.6
GroundConstruction - 1.2.1
HullcamVDSContinued - 0.1.8
JSIPartUtilities - 0.4.1
RasterPropMonitor - 0.29.3
Kerbal Engineer Redux - 1.1.3
Kerbal Joint Reinforcement - 3.3.3
KerbalLaunchFailure - 0.4.8
HyperEdit - 1.5.6
<b><color=#CA7B3C>Kopernicus</color></b> - 1.3.1.7
KSP-AVC Plugin - 1.1.6.2
KWRocketryRedux - 3.1.4
MagiCore - 1.3.1
Infernal Robots - 2.0.14
ModularFlightIntegrator - 1.2.4
Monthly Budgets - 4.1.0.1
NASA_CountDown - 1.3.6.2
NearFutureConstruction - 0.8.4
NearFutureLaunchVehicles - 1.1.4
NearFutureProps - 0.3
NEBULA_DecalsContinued - 0.1.2
Procedural Parts - 1.2.15
RealChute - 1.4.5
RealFuels - 12.6
RealFuels Stockalike Configs - 3.2.3
RealSolarSystem - 13.1
Recovery Controller - 0.0.2
US and Soviet Solar Panels Pack - 1.5
RSSDateTime - 1.2
SCANsat - 1.1.8.4
SolverEngines - 3.5
StationPartsExpansionRedux - 1.0.2
TAC Life Support - 0.13.6
TweakScale - 2.3.7 USI Core - 0.5.1
Konstruction - 0.3.1
MKS - 0.53.2
VenStockRevamp - 1.9.5