Both parties shall be relieved from satisfying this agreement, if its fulfilment is precluded, or essentially disabled by circumstances beyond their control or circumstances which could not reasonably be foreseen. The following and similar circumstances shall constitute reasons for relief, provided they hinder or aggravate fulfilment of the agreement: fire disaster, war, mobilization, requisition, confiscation, currency restrictions, common scarceness of goods, a deficit in means of transportation, strike, lock-out, power outages, deficits in driving means, and errors or delays caused by sub-contractor because of circumstance, mentioned in this paragraph, or other circumstance, which the parties could not possibly control, which either prevents or aggravates the parties’ fulfilment in such a manner that it could not be done other than to an unreasonably high cost.