Question about Adobe Illustrator.

We often draw different maps of Asia cities, which use complex fonts.
My Illustrator is set up to supporting east languages, including hieroglyphs.  
But after editing and saving, then opening, some fonts are converted to curves. Without dependency  of Adobe Illustrator version.
How can I fix this problem?
Not only the east language group presents this problem. Sometimes it appears with polish, spanish and portuguese language. Some ideas?

For example - vector map of Osaka, Japan:

https://vectormap.in...illustrator-nn/
That`s why we put "No correct street names" in the description, you know...

I am not quit sure why this is a problem.

Many vector art projects are supplied to the end user with fonts converted to outlines.

The outlines work for print and screen.

If the outlines are on a seperate layer, then the end user can edit as needed. (remove and replace with their own text)

It is unfortunate that you have lost control over this function.

I suspect that the files are very large and complex.

Illustrator sometimes converts fonts to outlines when "confused".

Adobe technical support may have some ideas about simplifying your computer system and font setup.

Many companies use Illustrator in cartography.

Adobe has some explaining to do.

https://forums.adobe.../thread/2388497

1. ctrl+A ( all design select)+ctrl+o(outline stock all fonts)

2. select path +outline stock (no change the path).