|There are two possible models. M2, which is USB 2.0 and M3 which is USB 3.0. The M3 requires more power, which is the reason for the double USB connection. See the link below to determine which you have. The case color accents are different.|
There is also a support link there to deal with specific issues.
As I stated above, IF all else fails you should be able to repair the partition, or recover data after a quick format, assuming you did not use their software, which can encrypt the data.
I suggest you try their support process first. 2.5" USB powered externals are more problematic than AC powered 3.5" models. Also, External drives MUST be properly removed, or corruption may occur.