According to https://developer.bitcoin.org/reference/rpc/listunspent.html
| values | datatype | description | |
|---|---|---|---|
| “spendable” | true/false | (boolean) | Whether we have the private keys to spend this output |
| “solvable” | true/false | (boolean) | Whether we know how to spend this output, ignoring the lack of keys |
What you do, presumably, is pick one or more to spend. Or otherwise fulfil the purpose for which you called listunspent.









