Poloniex exchange has delisted Steem SBD, so deposits of SBD are currently disabled. If you have Steem SBD stores on this exchange you should remove it or risk losing your cryptocurrency.
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Once the withdrawal deadline has been reached, withdrawals will be disabled and the delisted assets will be decommissioned. From that point forward, we will be unable to process withdrawals of the impacted assets. For more information about our delisting policy, please visit our Support Center article. We greatly appreciate your support."
Source: Poliniex exchange support page.
Thanks to@ketcom for the additional information.
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