Can't select Kerbin

[Chris_C]

I've encountered this issue during a number of versions of KSP, usually fiddling and faffing I can get it to select, in my current save I'm in orbit around the Mun and cannot select Kerbin, if I zoom out far enough I can click the small selection sphere that's usually in the centre of the planets (at a normal zoom it's not visible), however as soon as I do this it says no target

I can select other planets, but not Kerbin

both 32 and 64 bit versions behave the same.

here's a list of my GameData directory

ModuleManager.ConfigCache

ModuleManager.ConfigSHA

FPSViewer.dll

*TriggerTech

*000_USITools

*CommunityResourcePack

*Firespitter

ModuleManager.2.5.9.dll

*Regolith

*UmbraSpaceIndustries

*MechJeb2

*dockingtube

*Squad

*NASAmission

Has anyone else seen this or have any ideas about a solution?