I failed my undergraduate thesis and didn't get my degree certificate. Can I pass the second time?
You can pass. You can get a diploma if you fail to defend your graduation thesis, but you can't get a degree certificate. Thesis defense is the key to decide whether a student can get a degree certificate after graduation. If the defense fails, you won't get a degree certificate. There are two chances to reply. If the first defense fails, a second defense is needed. If you can't pass the defense all the time, you won't get a degree certificate. This situation is rare, unless you don't reply, you have already given a second reply.