UE4 navigation dose not function!

i am trying to use the navigation, after watching the cretin tutorials and the UE4 documentation, but the it doesn’t seems to work for me at all! when i place nav mesh bound volume, i see the box, but i can but see that green surface been created at all(the green surface which will cover the surface) and yes! i did resized the volume and try different locations. i thought i just can’t see it cuz of some view options but my AI navigation blueprints don’t work and all the option for viewing navigation are on, and also i made sure that all the Game blueprint option and project setting related to navigation system to be restored to default.but the navigation volume still don’t function,
am i missing something to do here, or there is bug with my editor?

Try with “P”, the green surface should appear

i said it on the details, i did made sure to make seeing the navigation active, beside even beside the fact that i can’t see it, also blueprints don’t function

If it was me i would try a verify in launcher first and then try to do a navmesh and a bp in another new project.

hi guys…the problem seems to be solved i think… i restarted my project, and this time it seems to working, however it’s taking so much more time that i thought it would to build, although that this time after i created another project, it now builds the nav mesh, but now that can so one please tell, me how i can increase the speed of building navigation at least long enough so that i can test it, i really think there is something that i done to the setting(in some tutorials i had to) which does not restored to default yet, do you have some ideas that what made the building navigation for the third-person example project(the one that come with the editor) about 4 hours??? i don’t have a top end pc, but it’s powerful enough to build an entire geometry and lighting under half hour,i don’t know why it takes to create nav mesh sop long.
does anyone know what parameters and setting affect the speed of creating navigation??? maybe i did something to them that i need to restore

I don’t know how to help you with that but i had some trouble with old project i had things in i liked like meshes or bp which could not start with the new engine. I just created a new project of the same type and add my old content merge with the new one, without replace new stuff. And i saved a lot of what i had. In hope it helps you too. If trouble comes from settings you’ll nat have them then.