xcollapse problem

I am doing something that should be simple but I keep getting the same error. Any help would be appreciated:

xcollapse v2x_corr, by(country year) saving{vdemcorr2)


You must specify at least one of the four options:
list(), saving(), norestore, and fast.
If you specify list(), then the output variables specified are listed.
If you specify saving(), then the new data set is output to a disk file.
If you specify norestore and/or fast, then the new data set is created in the memory,
and any existing data set in the memory is destroyed.
For more details, see on-line help for xcollapse.
r(498);

I tried to attach the data file but I got the message that the data file is invalid. It was created by Stata 14 using savesome. I am stumped.