Hey - Yes, we are not sure why this is happening. It could be the Windows Store, but we are speaking with Microsoft to see what where the bug is coming from. Really appreciate your patience.
I tried installing some other new apps .. Even that app shows the same error ..suddenly came the Messenger update rite now it got updated properly wen I tried true caller along with it ..True caller too got update!!
I have installed windows 10 yesterday, it seems in windows 10 for phones. Unable to select category for installing apps from truecaller and whatsapp which are just install on phone memory.