Dear all, I am using Stata 14 on Windows 10. The following code is supposed to create a combined graph of several scatter plots for two variables. I used almost the same code several times for other graphs and it worked. However, this time I always get the error message "Series 0 not found" after all single graphs for the respective countries have been generated, i.e. no combined graph is created (I only get an empty combined graph). After spending several hours trying to fix that problem, I have no more idea...

Code:
levelsof country, local(levels)

local graph ""

foreach i of local levels {
    summarize net_tradevalue_m if country == "`i'", meanonly
    local y_min = `r(min)'
    local y_max = `r(max)'
    
    local y_min_r = round(`y_min')
    local y_max_r = round(`y_max')
    
    scatter net_tradevalue_m instal if country == "`i'", ///
    xtitle("Number of items installed") ///
    ytitle("Import value (US$) net of re-exports") ///
    yscale(range(`y_min' `y_max')) ylabel(`y_min_r' `y_max_r') ///
    title("`i'") name(g_`i', replace)
    local graph "`graph' g_`i'"
}

grc1leg2 `graph', xtob1title ytol1title ytsize(vsmall) labsize(vsmall)
Code:
* Example generated by -dataex-.
year country net_tradevalue_m instal
2005 "AE"   .596557    3
2007 "AE"    .57997    2
2008 "AE"  1.334496    2
2012 "AE"    .82767    4
2013 "AE"   2.23105    2
2014 "AE"  3.857373    0
2015 "AE"  2.996899    0
2016 "AE"  3.456476    0
2017 "AE" 10.282882    0
2018 "AE"  6.563038    0
2019 "AE"  3.967778    0
1996 "AR"  2.930427    0
1997 "AR"  2.566672    0
1998 "AR"  2.713423    0
1999 "AR"  1.757973   20
2000 "AR"   .820514   50
2001 "AR"  1.731663   40
2002 "AR"   .433283   29
2003 "AR"   .693137   33
2004 "AR"   .537529   17
2005 "AR"  1.334015   65
2006 "AR"  1.607395   36
2007 "AR"  5.205558  141
2008 "AR" 13.348274  150
2009 "AR"  2.953936   45
2010 "AR"  8.285274   96
2011 "AR" 22.273457  407
2012 "AR" 15.632359  180
2013 "AR" 13.275552  181
2014 "AR" 10.507074    0
2015 "AR" 14.350166    0
2016 "AR" 11.726218    0
2017 "AR" 16.001951    0
2018 "AR"  9.526949    0
2019 "AR" 15.542093    0
1996 "AT"  9.284512  277
1997 "AT" 11.324429  232
1998 "AT"  11.18832  145
1999 "AT" 16.971384  273
2000 "AT"  37.53419  320
2001 "AT" 16.574034  330
2002 "AT" 16.691013  670
2003 "AT"  14.51144  365
2004 "AT" 24.916763  545
2005 "AT"  25.72232  485
2006 "AT" 35.112324  498
2007 "AT"  38.49554  621
2008 "AT"  46.18709  638
2009 "AT"  41.32523  508
2010 "AT"  36.71757  496
2011 "AT"  43.99167  628
2012 "AT"  40.30826  835
2013 "AT"   40.7037  720
2014 "AT"  51.64431  898
2015 "AT"  48.09217  987
2016 "AT"   73.0638 1686
2017 "AT"     81.19 1641
2018 "AT"  82.17607 1504
2019 "AT"  74.40486 1475
1996 "AU"  4.763878  250
1997 "AU" 10.905708  526
1998 "AU"  6.894873  347
1999 "AU"  8.601764  180
2000 "AU"  8.956798  440
2001 "AU" 10.291573  270
2002 "AU"  13.03586  421
2003 "AU" 17.182116  569
2004 "AU" 28.043364  652
2005 "AU"  29.79912  890
2006 "AU" 19.709654  719
2007 "AU"  26.95258  734
2008 "AU"  20.39395  781
2009 "AU"  8.937055  399
2010 "AU" 13.016978  624
2011 "AU"  17.47799  690
2012 "AU"   22.5622 1214
2013 "AU"  13.40527  323
2014 "AU" 11.591695    0
2015 "AU" 13.899048    0
2016 "AU"  16.18698    0
2017 "AU" 19.643173    0
2018 "AU"  28.74417    0
2019 "AU" 18.894983    0
2003 "BA"     .0334    0
2004 "BA"   .166554    0
2005 "BA"   .074738    0
2006 "BA"   .260394    0
2007 "BA"   .535262    0
2008 "BA"   .677682    0
2009 "BA"  1.532421    0
2010 "BA"   .381561    2
2011 "BA"  3.805619    2
2012 "BA"   .817377    0
2013 "BA"   .587407    0
2014 "BA"  1.019831    0
2015 "BA"   .604327    0
2016 "BA"   .752781    0
2017 "BA"  1.305355    0
2018 "BA"  1.188319    0
2019 "BA"  2.205264    0
end

It would be great, if someone could help me. Thanks a lot!