Error when trying to run my data but not sample data

Hi Everyone,
Just trying out metaSEM. Analyzing the sample data worked perfectly. Unfortunately, the error below occurs when I try to run meta3 with my data. Note that there are no missing or NA values in my data. Any help in trying to get this to run would be greatly appreciated!
Cheers,
David

First few row of myData (unsorted):
yCol xCol country yColSamplingVar
1 0.35000 39 51 0.0020375922
2 0.48780 35 53 0.0090533427
3 0.24500 36 14 0.0040732539
4 0.41600 60 33 0.0039870241
5 0.38000 54 16 0.0016615144

My Command:
metaHLMResults= meta3(y=yCol, v=yColSamplingVar, cluster=country,x=scale(xCol, scale=FALSE), data=myData);

Error Message in R:

Error in running the mxModel:

Running Meta analysis with ML
Error in running the mxModel:

Error in runHelper(model, frontendStart, intervals, silent, suppressWarnings, :
Error: NA value for a definition variable is Not Yet Implemented.
>

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David Stanley, PhD
Department of Psychology
University of Guelph
Guelph, Ontario
Canada N1G 2W1

office: 4002 MacKinnon
e-mail: dstanley@uoguelph.ca
phone: (519) 824-4120, x58590
web: http://www.uoguelph.ca/iopsychology/Stanley.shtml
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