The RaiBlocks (XRB) team announced from their twitter account today that they were working with the BitGrail exchange on a node issue. BitGrail reportedly stopped all deposits and withdrawals during the process and lowered all withdrawals to 1XRB.
The new RaiExchange responded on it's twitter account regarding the bug that it was a minor problem with a current workaround until the RaiBlocks team resolves the problem and hinted that BitGrail should be running more than one node. The RaiExchange is currently taking registrations for it's launch in the coming days.*Update: Both BitGrail and Mercatox have been reported back online and all funds safe.