Hi Zeinah Mohamad Elnassar

Probably the element size you selected is much larger than the dimensions of that small area. For the meshing, first, begin with that small area and select the edges and number of divisions. If you could achieve a good mesh, go to larger areas and do mesh transition as you get close to that small area.

Commands LSEL, LESZIE might help.

Best,

Ali

Try mesh with triangular shape elements.

Regarding the second and third errors, they refer to the "shape testing" of isoparametric elements, as that you are using. Such finite elements must be not too much distorted from the ideal quadrilateral shape - limits are usually listed in the software help. For the first error, I do not know

Do not use element size greater than the dimensions of that small area. Use lesser element size for meshing.