Hello Murali:
The first thing you need to verify that the downloaded file 'strikr.box' is complete.
The MD5 checksum of the vagrant box 'strikr.box' should be
e5b2edf1ce4029b9196903a356c4f671 strikr.box
Using the following command, you can calculate the MD5 sum
$ md5sum strikr.box
Could you please check and get back ?
warm regards
Saifi.