Error Code 39 Meaning?

[vasatrya]

Hi, I am trying to unjail a node on a blockchain created via Cosmos, and am getting the following error:

“failed to execute message; message index: 0: cannot delegate to validators with invalid (zero) ex-rate”

What does this error code exactly mean?

[julienrbrt]

How many delegations has the validator?

https://github.com/cosmos/cosmos-sdk/blob/f0d6e7717351ed998575e9cb2beafaa626ab78f2/x/staking/keeper/delegation.go#L681:L686

[vasatrya]

How can I check?

The chain I am running the node on requires 50k tokens. I recently moved the 50k tokens - if I update the staking address would that make a difference?