Error, (in HelpTools:-HelpCallUI) help database
might occur when either the Maple or user folder path contains non-English characters.
Please try the following:
Open the file
C:\Program Files\Maple 2019\bin.X86_64_WINDOWS\maplelauncher.l4j.ini
in a text editor.
Insert the following line, or make any necessary amendments (remove "# ", space included, from the existing language setting and change the value):
Save the file, and then test Maple.