every time i open an old project, the assets always get messed up, they became shapes/sprites with colors, ignoring the textures, it only fix when i double click that bugged object
Are your textures imported or drawn with piskel?
drawn with piskel yes
Then make sure the textures are saved to the project folder.
Do you mean that after fixing them and saving and reopening that project, the issue still occurs?
Did you move the project or edit the assets outside GDevelop?
Go to the resources tab and check if their path is right.
they are all saved in the project folder, (all created sprites get automatically saved in the project folder)
yes the problem is always there whatever i do, the resources is fine the path is fine and the objects are in the project folder, also this happens in most of my old projects
i just want to add, that this problem is happening with almost everyone, we discussed this on discord before and most of the users said it happened with them
i also want to add something maybe this can help figuring where this bug came from:
i find my objects in another projects
for example i have ProjectA (the face with tongue)
and i have ProjectB (rope object)
when i open Project A ,i find the rope objects (the brawn rectangles) in there
and when i open Project B ,i find the Eyes shape in there
its only visual bug when i double click on them they got fixed
even if i left them as they are and Hit preview, the normal shapes will view not the bugged one
And… their filenames are the same, perhaps? 
in piskel, yes, because the default naming is always (New object)…1 2 3…etc
in any project its always the same names, though each project use its own folder, but somehow Gdevelop is reading the same name from another project
also this only happenes to sprites that been draw in piskle.
imported sprites never have this problem,
i think you are right, the naming is the issue, Gdevelop is reading the file name from the wrong project folder somehow
here is the naming, yea its defentily the names who cause this bug
the last sprite (ZZZZE-1) i draw it in piskel and in the same time i changed the name to ZZZE inside the pskel editor, then i saved and closed the project and gdevelop
when i open the project again, everything got bugged except the sprite ZZZE had the same sprite i did draw