I have an older wallet which does not have a 12 word master seed, but does have a 15 word password.
Can you elaborate?
What do you mean with "15 word password" ?
Do you actually have a mnemonic code with 15 words? Because, they exist.
Do you remember where or how you actually got the 15 words?
My wallet was a single address + HD account (which contains my btc) . I am able to recover the actual single address, but don't know how to access the HD account that was associated with it...
The HD account is not associated with your "single address account".
They are completely seperate.
The "single address account" is simply a private key stored in mycelium and the HD account is a seed from which all private keys are derived.
You need the mnemonic code to access your coins (which might even be the 15 words).
I have read that all I need to do is recover the wallet and then add a new HD wallet and it should get discovered.
This is the case when someone has had a second HD account which also is derived from the same mnemonic / seed.
Then simply adding another account will resolve the "my 2nd account is missing" problem.
But since your mycelium wallet only contained 1 HD account, it is the "first" one which is missing.
Could you please answer:
- Where did you initially create the wallet (15 words ) ?
- What operating system version is running on your mobile?
- Is your smartphone rooted?