I accidentally entered a 1099 MISC twice so I deleted one of them. The system keeps telling me I didn't enter amount on line 7. I only have one 1099. It thinks I have 2.

Type '1099misc' in the Search window, then 'Jump to 1099misc'.

At the 1099-Misc Summary page, you can Delete an incorrect entry (screenshot). 

Or, you can Delete a Form from your return:

https://ttlc.intuit.com/replies/3288508