The fact that he database drop-down is blank suggests to me that the backup file is invalid/corrupt in some way.
First, try and restore the backup file header to confirm that the file is a valid SQL backup. In Management Studio, connect to your SQL 2016 instance and open a new query window. Run the following:
RESTORE HEADERONLY FROM DISK = 'C:\Users\nasscribe\Documents\sibk\sibk'
If you receive an error from this query, either it is not a valid SQL backup file (possible that there was a write error during the backup process on your 2008 R2 instance, or you just grabbed the wrong file), or it is a permissions issue where the SQL Service account cannot access the file, and you'll see something similar to below:
Msg 5120, Level 16, State 101, Line 1 Unable to open the physical file
"C:\Users\nasscribe\Documents\sibk\sibk". Operating system error
5: "5(Access is denied.)".
If you receive the above message, copy the backup file to somewhere like C:\Temp\ and retry.
If instead you see an error like this:
Msg 3241, Level 16, State 0, Line 3 The media family on device
'C:\Users\nasscribe\Documents\sibk\sibk' is incorrectly formed. SQL Server cannot process
this media family.
Msg 3013, Level 16, State 1, Line 3 RESTORE
HEADERONLY is terminating abnormally.
Then the backup file is not a valid SQL backup. Provided you still have access to your old server, connect to it and re-run the backup:
BACKUP DATABASE TO DISK = '[Backup path here]\sibk.bak' WITH STATS=5
Once done copy it over to your 2016 server and run the restore again.