I applied freeze sending. I then tried to force-close it but it failed: "bad-txns-inputs-missingorspent"
Any pointers?
If the locktime (height or time) is still not reached, the error message alongside with the server error should be "non-final".Any pointers?
That looks like a missing input error which was caused by trying to double-spend a already spent output or not-existed at all;
Can you check your wallet for possible closing transaction that wasn't labeled?
Paste the "open channel" transaction's TXID (in a block explorer) and check the non-change address output if it's already spent.
Also check if it was sent to one of your own wallet's addresses.
If there's no "open channel" transaction, perhaps there's no established channel to begin with.
How come the channel status keeps saying "reestablishing" after so long without automatically unlocking it??
If it didn't see a confirmed closing transaction, it won't transition to "Closed" but rather stay "Open"and "Reestablishing" is a state based from the other peer of the open channel, means the channel is open but trying to re-connect to the other LN node.
There's an "Open channel" entry in History. However, the transaction ID doesn't show up in the blockchain after trying to explore it. ( I abandoned the attempt to open channel with a merchant and I did not sign the transaction).
How could I retrieve my locked funds? It's been forever in locked state.