Error in master's thesis, I do not know what to do I successfully defended my master's thesis last December.
 I had 18/20 and it went well. However, my adviser invited me to carry out research in the area, which I accepted. 

When I was writing the first paper, I noticed a big error in the data analysis. This does not affect the conclusions and the values of the estimates are very similar (with and without the error) the question is what do I do now? I'm afraid to tell my advisor and they cancel my master's degree. What do you think? My ethics does not allow me to write the paper again with the error, but if correct my advisor will find .. 

Any suggestions? I'm sure no one will notice the error, but I do not know. 
I´m very afraid of this
Thank You
Revoking an earned degree is exceedingly rare and would probably be appropriate only for serious and intentional errors such as fraud. I think you can rest easy on that. 

Talk to your advisor and lay it all out. It is better that you find and reveal the errors than if someone else does. Going forward you can still publish, but it will need to be based on correct data, analysis, and interpretations. 

It is common in research for errors to appear in old work. It is certainly not a unique occurrence. Attempting to conceal it would be the worst path of all.