LocalDB Connection Failed

Recent project attempt to abandon sqlexpress2005 use LocalDb2014, encountered problems: LocalDB installation success, can normally add instances, but the same WinForm program on different Win7 computer some can connect, and some how can not be connected to the database, The exception will pop up: (Provider:sql Network Interfaces, error:26–error locating server/instance Specified). there is very little information on the web, and there is a website explaining the problem. https://blogs.msdn.microsoft.com/sql_protocols/2007/05/13/ sql-network-interfaces-error-26-error-locating-serverinstance-specified/. But it doesn't seem to apply to localdb.

The operating system I tested was Win7, and I tried to find out that installing the SQL Management tool Sqlmanagementstudio (which I had 2014) (which required Win7 SP1) could be connected, but it was cumbersome. Inconvenient to install on customer's computer. Discover the installation with the constant attempts of colleagues. Net4.5 can also be connected, very happy. The official web site does not indicate the need. net4.5 environment, I understand that there may be an update in net4.5 that solves this problem.

LocalDB Connection Failed