Game keeps crashing when I buy spells.

[ApollymiAcheronBraith]

I am currently working on the mage guild quests after i have already completed the arena and fighters guilds. when i go to the shop in the imperial city mystic emporium and buy all the spells from either character the game crashes. i have tried buying from both and the result is the same. buy all the spells game crash.
any suggestions?

[ApollymiAcheronBraith]

btw i dont have any mods

[Wai]

My initial thoughts on this, as you are playing vanilla, is that you have a corrupt file. Have you tried going back to an earlier save and then trying to buy the spells?

Long play sessions can cause problems. Try to save and return to the main menu quite frequently.

[ApollymiAcheronBraith]

good advice ill start doing that

[Other]

You say you don't have any mods, but are you using any (or all) of the official DLC's? Two of the DLC's (Wizard's Tower and Fighter's Stronghold) make changes to Mystic Emporium. At least some of the Steam versions of Oblivion include all the DLC's by default.

[Deadmarch]

I had a same issue. But I found simple workaround. 

Symptoms:
failure occurs after i buy the last spell from the seller's list and right after I make a movement with my mouse.

Solution: 
Make a click with a left mouse button to buy the last spell as usual.
Now, take your hands off the mouse!
Use upper arrow key on keyboard to confirm a buy of the last spell. 
Press ESC key to display main menu. 
Now make a movement with your mouse.
And now you can safely return back to play your game.

https://youtu.be/kZILrY7oCTI

[KillerX629]

Holy christ, just had this crash twice, searched without any hope and found this. the EXACT same bug. I think this has to do with using upArrow key to buy items, seems like it's not much of a feature but a bug.