So there are two versions you need to load. https://indivi.itch.io/ldplus/devlog/390570/missing-graphic-errors-in-r38
The way the graphics are filed changed, so you need to load your save into that version in order to migrate it further forward as it will convert it. There was also a combat one at some point, I do not recall what upgrade, if you run into a bug were enemies don't die at zero hp its do to that one, Like the graphics one you may fix it by upgrading to the patch right before and then up one before going all the way, but I do not know what version that was, try the graphics one first, if combat works you dodged the bullet.
here is a achieve of builds https://mega.nz/folder/M4U1mDrR#P8KOwqwwy9lQqG3fLRpcCw
grab r37 and r38 and upgrade to them, or if you really want to play it safe grab all and upgrade one at a time by opening your save in each saving and doing it in the next one. make sure to make backups and check for the combat bug.