rico
It's a warning only.
AFAIK, this really depends on MODX core's feature to have nested contexts. I am not sure it has been implemented programatically, IIMW there is a "parent" field in context's table.
ext-all.js in uncompressed format is available on on MODX sdk version
at the end, you need to create different **cultureKey** settings into each context. so I don't follow your saying "same lexicon may be used". that said, the lexicon's structure should...
you use path for the translation? www.domain.tld/en/xxx.html www.domain.tld/fr/yyy.html
which gateway plugin are you using?
how about your htaccess?
Let's try the common solution first add `fr/` path to the main website as well. redirect initial visit to fr/ context if no language path is defined.
For quick fix, try to replace $this->modx->cacheManager-> with $this->modx->getCacheManager()->
And please make sure your cache folder's permission is 0777