Due to number of crevasses caused by a new ice-cauldron on Vatnajökull glacier east of Grímsfjall, the mountain should be approached from west and north, not east, as until now has been possible.
More information on the Safetravel page.
This is due to changes in the glacier that took place in connection with jökulhlaup flood from the Grímsvötn subglacial lake. More information about the jökulhlaup can be found here.