my inventory and sience keeps resetting plus I can't use slots 2-5

how can I reinstall or reset the game?

you have to mention, if you are playing beta or not.
You have to mention all the mods you use (if playing with mods, diable all of them and try again -> find out which mod is causing it)
And you have to post your logfile.

no mods.. it's the game... how can I reset the game?

22 minutes ago, DisGo said:

no mods.. it's the game... how can I reset the game?

- Open Steam
- From the Library section, right-click on the game and select Properties from the menu.
- Select the Local files tab and click the Verify integrity of game cache... button.
- Steam will verify the game's files - this process may take several minutes.

If this still doesn't work, then please reply and attach your log files.

Here's the instructions with a nice animation: https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335