You will need to start a new game.
If you want to continue old saves go to: https://www.nexusmods.com/mbwarband/mods/6317?tab=files and download version 1.21

Update 1.3 changelog:

Major Additions:

• added option to buy land next to a village (by talking with the village elder/now called local leader): a latifundium will spawn near that village (as new party) and you can build stuff on that land, the buildings will show up on the scene. (Under game concepts you have more info on this)
  
• added new treaty option: tributary vassal: if a kingdom is winning a war against a 'barbarian' one, then, if the kingdom is large enough and if the kingdom has inflicted enough war damage the barbarian kingdom will become the tributary vassal of the other kingdom.
  Currently only available for the AI. It is also in an experimental stage and therefore optional.
  added Parthian expedition forces: Once the Parthian empire is defeated, an expedition force can spawn: It is a huge experienced army which will attack Ctesiphon. (this can only happen once in a game)

Minor Changes:

• Some people ask me to make Darta able to marry, I decided not to do it, but instead I created a new lady, who looks like Darta. She is the daughter of Tiberius Claudius, the governor of Carthago. Her name is Claudia Tullia. (ask her ‘May I have the honor of knowing more about you, my Lady’ to find out more about her...)
  
• changed germanic lord equipment: they now have throwing spears, a shield and a ax. And instead of running around shirtless, they now have a nice mail shirt
  
• If a lord surrenders and the player accept the ransom he offers, the lord party will be spawned as routed enemies party, the routed enemies will flee to the next castle and reinforce the garrison there
  
• If bandits surrender now half of them can be taken as prisoners by the player
  
• changed how money from slaves in your villages is calculated: now you gain 50 per slave, if you have a sliver mine another 60 per slave, for silver deposits another 30 per slave, for iron deposits another 20 and for iron mine another 40 per slave
  modified is this all by a factor, which depends on how you treat your slaves (e.g. very harsh will give you +15%)
  
• reworked some governor events (events when visiting the town), emperor events (events when leaving the palace) and some normal events (events while traveling)
  e.g. some events like the 'you encounter some runaway slaves' are now replaced by others
  
• increased prices for village volunteers from 10 to 100 per man
  
• added horse races for Roman culture towns, you can now choose between a horse race or the normal arena fight during tournaments
  
• changed how sacrifices work: you wont gain any renown now (renown is won on the battlefield, sacrifices are done to 'clean your sins'. The honor you gain is increased and the costs too.
  Additionally, you can now only make one sacrifice a day (either by a priest or at Delphi or at a German holy side).
  
• You can now build your own temple in towns and castles and decide to witch deity the temple shall belong (Christian and Jewish options are only available if you are Christian or Jewish): Once the temple is build you can visit it from the town center menu.
  
• you will now lose renown if you are knocked out during a battle
  
• added short cut to access priests in Roman temple scenes: if you have visited the scene once you can spawn on the scene next to the priest by pressing the shift key (either left or right) (also some changes to the temple scenes and the code)
  
• issuing a senate meeting now costs money and influence
  
• added refine armors dialogue option with armor merchants
  
• added new quest: You need now to bribe the rest of the praetorian guard with 1 Mio. denars to become Emperor (Kaeso Flavius alone is not influential enough). This should force players to build some kind of power base before becoming Emperor
  
• added stances: default, screening forced marsh, which effects ambush propability
  
• created a new castle scene, replacing the last native castle scene, its the generic eastern castle scene.
  
• changes to ambushes:
  
  • probability is effected by: culture: barbarians ambush more often, Romans don't ambush at all (like in previous version), your tracking skill (like in previous version), your party stance (new), terrain (now has increased impact)
    
  • added a little surprise for ambushes
• added an option to disable the "enemies spotted" messages
  
• added message which displays how much food is left.
  
• added a new companion mission to stage unrest in a settlement
  
• added a new option to embezzle founds from the imperial treasury: it is only available as censor: the option is available via the senate menu ('inspect the imperial treasury')
  you can embezzle as much as you want but the more you embezzle, the more likely you will get caught. If you get caught, you can bribe the official, leading the investigation, but he will demand half of the money you have embezzled (in total!, e.g. if you have embezzled 10,000 denars and are caught, but you have embezzled 90,000 denars before, he will demand as bribe 50,000 denars)
  if you don't have the money you will receive a huge relation hit with Nero and a renown and honor hit, depending on the amount you embezzled in total. You will also have to repay all the embezzled founds (it will be added to your debts, e.g. if you embezzle 600,000 denars and are caught you have to repay it)
  
• made three villages to castle to make sure, that every faction now has at least 1 castle and 1 town or 3 castles
  
• distributed the training grounds over the empire and renamed them to Ludus
  
• added new building; temple, you can decide to which deity the temple shall belong. (christian and Judean only are available if you are either christian or judean)
  
• renamed village elders to local leaders (as I think village elder does not fit for Roman villages)

Bug Fixes and balance changes:

• made sure that dead or inactive lords can not do one of the political events (borrow gold, lower relation, bring jewelry)
  
• fixed a ‘hash vector failed at index -1‘ bug in the empire report which was caused by an invalid party (this happened if a legatus legionis was defeated and didnt respawned again)
  
• changed how damage to allies of player is inflicted when enemy manages to ambush you or when "you were surprised by enemy missile troops" happens
  
• lowered casualties which can be suffered by random attacks during sieges (to prevent garrisons killing themselves)
  
• fixed script error in lover report
  
• changes to "bribes" of lords: you can choose now if you get any support or not, and support now depends more on relation of lord with Nero, the relation must be at least greater than 25!
  
• speeches reduce controversy now depending on skill and a failed speech will increase controversy
  
• added (hopefully all) missing entry points for large battlefield maps
  
• leader of faction can now no longer be ordered to join your army as marshal
  
• some changes to faction restoration to hopefully fix any bugs which may occurred there
  
• towns/castles where a rebellion is currently processing will no longer be a valid target of another faction, fixing hopefully any bugs
  
• attempt to fix dismounting cavalry by ordering them to mount at the start of the battle.
  
• a minor change to sack town/castle script to hopefully prevent rare bugs which may cause centers switching factions
  
• lowered senate support from speeches, it is much lower now (support changes now between 1 to maximal 4 senators depending on your skill)
  
• minor change of the "exterminate population option": option is available now if you have more than 200 men in your party and if you either have a negative relation with the center or if the population is of another culture
  
• changes to the lord defection and lord indicted for treason code: it should no longer be possible that lords commanding a legion, aux unit or governors defect! Additional: if a defection happens, lords will prioritize factions with the same culture they have
  
• changed another native code which let lords randomly switch factions if several arguments are satisfied: Now this can only happen if both factions have the same culture, e.g. Roman lord switch during civil war from one roman faction to the other is still possible.
  
• fixed again budget report not displaying everything (hopefully the final fix)
  
• other change to a code (cf_get_random_active_faction_except_player_faction_and_faction), which decides to which faction a lord from a defeated faction changes has been made:
  now, only neighbor or factions of same culture are possible targets (this should prevent e.g. Armenian lords going to kingdoms in Britannia when Armenia is defeated)
  
• increased the amount of money towns/castles gain to recruit garrisons (only for AI), this should prevent town wealth becoming negative, will also lead to an increase of non-Roman garrisons
  
• fixed a case where a castle/town could switch factions:
  center get sacked, then the lord switches to another faction, then when it recovers it changes to the old faction of the lord
  Now it will be assigned to the lord faction if the old faction of the center and the lord faction do not match
  
• fixed messenger post not showing up in villages if it has been constructed
  
• added a strength check when deserters and rebel parties decide which village they will loot (similar to the lords AI)
  
• fixed a script error with rebellions
  
• lowered upgrade costs for high level troops
  
• fixed a script error in dialogue with your lover during usurp province quest
  
• companion report now has a proper scroll-able overlay to display companions
  
• removed relationship between pretenders and kings (since pretenders are disabled)
  
• fixed player odds at game start for some towns
  
• removed a corrupted music file
  
• reworked caravan battle scenes
  
• reworked a lot of stats, mainly for archers/skirmishers (to make them less skilled in melee but more in range)
  
• added throwing spears to a lot of non roman units which probably would have used one
  
• spears and twohanded weapons (e.g. flax from Dacians) will not be shown on the back of troops when not in use (I never liked it, it is ugly)
  
• troops leveling is now much easier
  
• cavalry is now much more expensive to maintain
  
• now you only get money from gold/silver mines if the village to which they belong is not infested by bandits or looted (which is reasonable, as you wont get any rents from the village too)
  
• lord-npcs should now lose honorary titles less frequent if Nero gets angry with them
  
• increased npc wages for nomadic culture
  
• some attempts to prevent renown from becoming to high for AI lords and kings (especially you, Nero!!)

Known bugs:
- traveling through the English channel with ship is not possible. Your party will travel all the way around the British islands to get from one side to the other side of the channel. (I know the reason for it, but its not that easy to ‘fix’)
- Some armors are invisible in the troop tree.
- The “Mounted ballista” (the ballista you can use on a mount) has a small graphical glitch when it is in inventory. (but on the battle field it looks fine)