ERROR: The current FPC has no config file. It will probably miss some units ...

[BubikolRamios]

I guess fpc is instaled correctly as my current project works OK.

Opening some old project. It appears I installed ZEOS lib OK, as now I can open form at design time.

Error from thread subject, at opening project.

Then:

The project uses target OS=win64 and CPU=i386.
The system.ppu for this target was not found in the FPC binary directories.
Make sure fpc is installed correctly for this target and the fpc.cfg contains the right directories.

trying to run:

Compile package FCL 1.0.1: Exit code 1, Errors: 1
Error: Illegal parameter: -Twin64

[marcov]

Set the CPU to x86_64.

[BubikolRamios]

Nope, does not help/work at all.
After this and that, undocumented, had to replace libmysql.dll with libmysql50.dll found at https://www.dll-files.com/. Former lib namely not compatible with target, does not say with what of target options.

Thanks.

[Thaddy]

Versioning of the correct dll/shared library is YOUR responsibility. Not the tool you are using.