I've repeatedly downloaded and undownloaded Minecraft Java Edition and I keep getting the error message "Sorry, unable to start Minecraft. Please check your configuration". I have not downloaded any mods since I just wanted to play vanilla Minecraft.
Hi there!
This looks like a duplicate of MCL-14369.
Follow the instructions given in the Note on that report. If the instructions do not help you, try clicking on the link to the Community Support Discord. There are a lot of people there who are more than willing to do their best to help you fix your problem.
If none of this helps you at all, just keep an eye on that report.