Can´t see the hard drive

I have here in my office a WD Mycloud EX2 for a couple years now. there are 9 computers in the office plus some laptops and we all have to look into the external drive for archives, etc. Normally the hard drive can be seen in the net of each computer or can be access by icons of direct access. Still on many oportunities some computers can not see the hard drive, no matter what you do, the hard drive does not appear in some computers while it does appear in other computers normally. strangely the day after or after a few days the computers begin to see the hard drive normally !!!
What is happenig here? how can I solve this? is there any special configuration?

Thanks a lot

Have you tried manually mapping a Share in those computers so they can always remember the network path used by your WD My Cloud EX2?

In order to map a network drive please visit the following link: