QUESTION:
I want to open a configuration made with Pro Tool V1.x with a more recent Pro Tool software. What must I watch out for?

ANSWER:
A configuration made with Pro Tool version V2.0 or higher only has one PDB file.
If you have created a configuration with Pro Tool Version 1.x then an additional folder is created for the PDB file bearing the same name.
If you now open the configuration made with Pro Tool V1.x under, for example, Pro Tool Version 2.51, then the PDB and the folder with the same name must be available.