Permission denied when signing transaction on testnet

Developers Misc Dev Talk
2

I had a problem with my --signing-key-file $(addr1/payment1.skey) flag because it is missing cat.
Should’ve looked like this: --signing-key-file $(cat addr1/payment1.skey).

Now I get the following problem:

Shelley command failed: transaction sign  Error: Error reading signing key: {
    "type": "PaymentSigningKeyShelley_ed25519",
    "description": "Payment Signing Key",
    "cborHex": "5820afd61ccfc71a4ae44987caebc7fcdb89dddead58c80ccb98a82069e5c80dea96"
}: {
    "type": "PaymentSigningKeyShelley_ed25519",
    "description": "Payment Signing Key",
    "cborHex": "5820afd61ccfc71a4ae44987caebc7fcdb89dddead58c80ccb98a82069e5c80dea96"
}: openBinaryFile: does not exist (No such file or directory)

I see this issue was posted in this forum here but was never solved.