Error opening pool ledger connection

I Have two instances (instance A and instance B) both are Ubuntu 20.04. I am trying to connect the Instance A node to Instance B using the Genesis file. when I try to connect. This error occurred.

`Error opening pool ledger connection`

I am using this command to start `GENESIS_URL=file:///home/ubuntu/genises/genesis.txt LEDGER_SEED=000000000000000000000000SomeSeed PORT=9000 python -m server.server`

Start by reproducing the failure with the provided GENESIS_URL, LEDGER_SEED, PORT, and `python -m server.server` command across the two Ubuntu instances. Read the server startup and ledger-connection entry points to identify where `Error opening pool ledger connection` is emitted. Done means the connection from instance A to instance B opens successfully, with the failure cause documented or covered by a test.

Written by the indexing model from the issue text.