This issue is most probably caused by the incorrect entering of your backup phrase. Your 12-word backup is very sensitive to all kinds of spelling mistakes, words order, and spaces.
- All words are from this list: https://github.com/bitcoin/bips/blob/master/bip-0039/english.txt
- All letters are lowercase. No capital letters at all.
- No numbers at all.
- No space at the beginning and no space at the end.
- Only one space after each word, but the last word.
What else you can do:
- Check if all the words you are entering are part of the https://github.com/bitcoin/bips/blob/master/bip-0039/english.txt they are taken from. Search word by word. If any of the words are missing from the list, try to put in the phrase similar ones from the list until you bypass the warning " oops.Looks like the words you typed aren't a valid menemonic seed.check for a typo and try again". This means that you need to keep searching. Although that word is in the list, it wasn’t the one that unlocks your wallet. Only the specific 12-word phrase you had in the previous wallet will open that exact wallet.
- Tutorial video How to enter the 12 word seed : https://youtu.be/GL-ibcWG8Wk
Please note, that we don't store your backup phrase. We are not able to provide it to you in case you've lost it or saved incorrectly. The best way to save your phrase is to keep it offline to prevent compromise. Have a look at these articles to learn how to keep your funds safe: