ios - Storyboard: still "Unable to write to path" after deleting folder in Derived Data -

here's exact error

/users/colesmith/desktop/ui/sysco/base.lproj/main.storyboard: compilation failed. unable write path: /users/colesmith/library/developer/xcode/deriveddata/sysco-ezcmchmwlezfctayjgelgubgjqsg/build/products/debug-iphonesimulator/sysco.app/base.lproj/main.storyboardc 

i've tried everything. adding in new storyboard , replacing existing one. i've tried cleaning project, , i've tried new schemes, , deleting folder in deriveddata no luck. repaired disk permissions.

this started randomly when working. got error 1 build , haven't been able resolve it.

the storyboard contains hours of work , devastating lose. advice appreciated!

cole's answer correct! encountered similar problem. 1 view controller have storyboard id: "mega6/45vc". fixed change "megavc". maybe,problem character "/".