Sometimes exchanges can regularly (or inadvertently) remove API access for CoinTracker. Luckily, the fix is straightforward.
Create a brand new key on the exchange (some exchanges do not allow an old key to be used a second time)
Ensure that you have enabled all the requested read-access permissions per the instructions on the add exchange page
Ensure that you are entering all of the API credentials correctly, including any passphrase generated with the API key. Some exchanges, for example Coinbase Pro, require a unique passphrase specific to each API key you generate
Ensure that the API key is activated via two-factor authentication and email confirmation (if applicable)
Confirm that you have not turned on any IP restrictions for the API key (we plan to support this in the future)
Confirm that the exchange account has been used and is not empty or without any trasactnions. Some exchanges, for example Kraken, do not allow empty accounts to sync via their API to a third-party service such as CoinTracker
If you haven't been able to add the exchange: try to re-add the exchange. If it's already added but not syncing, navigate to the wallets page to the exchange that is showing the issue (or failing to add) and select > "Update API Key"