while trying to reproduce the example, i ran into some confusion myself... I downloaded the fonts and installed them, then ran the script: mtxrun --generate mtxrun --script font --reload context --make verifying the existence of the font within the context region: mtxrun --script fonts --list --all --name jost | cut -d" " -f1 shows the font appeared to be installed: jostblack jostblackitalic jostbold jostbolditalic jostbook jostbookitalic josthairline josthairlineitalic jostheavy jostitalic jostlight jostlightitalic jostmedium jostmediumitalic jostnormal jostregular jostsemi jostsemiitalic jostthin jostthinitalic Now when i compile the example, lmtx will shows an issue with the font: preloading latin modern fonts (second stage) fonts > 'fallback modern-designsize rm 12pt' is loaded fonts > names > font database has mismatching configuration and file hashes fonts > names > warnings are disabled (tracker 'fonts.warnings') fonts > names > identifying tree font files with suffix 'otf' fonts > names > scanning path '/home/vm/data/context/tex/texmf-project' for otf files fonts > names > 0 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-fonts' for otf files fonts > names > 0 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-local' for otf files fonts > names > 0 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-modules' for otf files fonts > names > 0 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-context' for otf files fonts > names > 1 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-linux-64' for otf files fonts > names > 0 otf files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf' for otf files fonts > names > 222 otf files checked, okay fonts > names > identifying tree font files with suffix 'OTF' fonts > names > scanning path '/home/vm/data/context/tex/texmf-project' for OTF files fonts > names > 0 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-fonts' for OTF files fonts > names > 0 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-local' for OTF files fonts > names > 0 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-modules' for OTF files fonts > names > 0 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-context' for OTF files fonts > names > 1 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf-linux-64' for OTF files fonts > names > 0 OTF files checked, okay fonts > names > scanning path '/home/vm/data/context/tex/texmf' for OTF files fonts > names > 222 OTF files checked, okay fonts > names > 446 tree files identified, 0 skipped, 0 duplicates, 446 hash entries added, runtime 0.045 seconds and it will fallback to the default lmroman12-regular I noticed that if i omit the context --make and only run mtxrun --generate mtxrun --script font --reload then compile the example, lmtx will show a different set of issues. Most likely related... open source > level 1, order 1, name 'cont-yes.mkiv' system > system > ConTeXt ver: 2019.12.17 16:30 MKIV beta fmt: 2019.12.22 int: english/english system > system > 'cont-new.mkiv' loaded open source > level 2, order 2, name '/home/vm/data/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv' system > beware: some patches loaded from cont-new.mkiv close source > level 2, order 2, name '/home/vm/data/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv' system > files > jobname 'j2', input './j2', result 'j2' fonts > latin modern fonts are not preloaded languages > language 'en' is active open source > level 2, order 3, name './j2.tex' fonts > preloading latin modern fonts (second stage) fonts > 'fallback modern-designsize rm 12pt' is loaded fonts > defining > font with asked name 'jost-100-hairline' is not found using lookup 'file' fonts > defining > unknown font 'jost-100-hairline', loading aborted fonts > defining > unable to define 'jost-100-hairline' as 'JHair--0' fonts > defining > font with asked name 'jost-200-thin' is not found using lookup 'file' fonts > defining > unknown font 'jost-200-thin', loading aborted fonts > defining > unable to define 'jost-200-thin' as 'JThin--0' fonts > defining > font with asked name 'jost-300-light' is not found using lookup 'file' fonts > defining > unknown font 'jost-300-light', loading aborted fonts > defining > unable to define 'jost-300-light' as 'JLigh--0' fonts > defining > font with asked name 'jost-400-book' is not found using lookup 'file' fonts > defining > unknown font 'jost-400-book', loading aborted fonts > defining > unable to define 'jost-400-book' as 'JBook--0' fonts > defining > font with asked name 'jost-500-medium' is not found using lookup 'file' fonts > defining > unknown font 'jost-500-medium', loading aborted fonts > defining > unable to define 'jost-500-medium' as 'JMedi--0' fonts > defining > font with asked name 'jost-600-semi' is not found using lookup 'file' fonts > defining > unknown font 'jost-600-semi', loading aborted fonts > defining > unable to define 'jost-600-semi' as 'JSemi--0' fonts > defining > font with asked name 'jost-700-bold' is not found using lookup 'file' fonts > defining > unknown font 'jost-700-bold', loading aborted fonts > defining > unable to define 'jost-700-bold' as 'JBold--0' fonts > defining > font with asked name 'jost-800-heavy' is not found using lookup 'file' fonts > defining > unknown font 'jost-800-heavy', loading aborted fonts > defining > unable to define 'jost-800-heavy' as 'JHeav--0' fonts > defining > font with asked name 'jost-900-black' is not found using lookup 'file' fonts > defining > unknown font 'jost-900-black', loading aborted fonts > defining > unable to define 'jost-900-black' as 'JBlac--0' backend > xmp > using file '/home/vm/data/context/tex/texmf-context/tex/context/base/mkiv/lpdf-pdx.xml' pages > flushing realpage 1, userpage 1, subpage 1 fonts > defining > font with asked name 'jost-100-hairlineitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-100-hairlineitalic', loading aborted fonts > defining > unable to define 'jost-100-hairlineitalic' as 'JHairI--0' fonts > defining > font with asked name 'jost-200-thinitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-200-thinitalic', loading aborted fonts > defining > unable to define 'jost-200-thinitalic' as 'JThinI--0' fonts > defining > font with asked name 'jost-300-lightitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-300-lightitalic', loading aborted fonts > defining > unable to define 'jost-300-lightitalic' as 'JLighI--0' fonts > defining > font with asked name 'jost-400-bookitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-400-bookitalic', loading mtxrun --generate mtxrun --script font --reloadaborted fonts > defining > unable to define 'jost-400-bookitalic' as 'JBookI--0'mtxrun --generate mtxrun --script font --reload fonts > defining > font with asked name 'jost-500-mediumitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-500-mediumitalic', loading aborted fonts > defining > unable to define 'jost-500-mediumitalic' as 'JMediI--0' fonts > defining > font with asked name 'jost-600-semiitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-600-semiitalic', loading aborted fonts > defining > unable to define 'jost-600-semiitalic' as 'JSemiI--0' fonts > defining > font with asked name 'jost-700-bolditalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-700-bolditalic', loading aborted fonts > defining > unable to define 'jost-700-bolditalic' as 'JBoldI--0' fonts > defining > font with asked name 'jost-800-heavyitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-800-heavyitalic', loading aborted fonts > defining > unable to define 'jost-800-heavyitalic' as 'JHeavI--0' fonts > defining > font with asked name 'jost-900-blackitalic' is not found using lookup 'file' fonts > defining > unknown font 'jost-900-blackitalic', loading aborted fonts > defining > unable to define 'jost-900-blackitalic' as 'JBlacI--0' pages > flushing realpage 2, userpage 2, subpage 2 close source > level 2, order 3, name './j2.tex'