What is the risk when working in multilingual environments?

The language of an estimate may be different from the language of the interface (ribbon).

The content of the Description column in a database may not be adapted to the Minutes (different native languages).

What should we take into account to prevent problems?

To switch to another language on the fly, set it in the Options, then select a column in the Minutes view or a database table (in edit mode), right-click and select the menu Default Columns Titles and reselect the language.

What is adapted when opening an estimate? What is not?

The language of tabs and headers is determined by the current language in File>Options. In other words, when you open an estimate, it opens with the latest language set in File>Options. However, the language of the ribbon is the one when QDV7 was opened for the last time. To remedy this, exit and reopen QDV7.