.NET v4.6.1 framework is rolling out across the domain where I work and is breaking .NET v4 applications deployed by ClickOnce. In particular the error message is "No connection string named <> could be found in the application config file.
Up to now my work around has been to uninstall v4.6.1, the install v4. About 50% of the time this resolves the problem with the v4 program. The other 50% of the time when the v4 program is launched another error is thrown which is "Could not load file or assembly System, Version=2.0.5.0 in .NET 4 MVC 4 application" This was solved using the suggestion from this page [ Could not load file or assembly System, Version=2.0.5.0 in .NET 4 MVC 4 application ] to install MS KB2468871 [ https://support.microsoft.com/en-us/kb/2468871 ].
Now I have a computer that requires 4.6.1 so I can no longer solve this problem by correcting the symptom of removing 4.6.1. Would my .NET v4 application be using v4.6.1 at runtime, and if so, is there a change in the way the application config file is searched for in v4.6.1 for ClickOnce programs?
UPDATE - this page states that when .NET 4.5 is installed, all .NET 4 programs will run under v4.5+ and that v4.0 and v4.5+ cannot coexist. So my v4.0 program is being hosted by v.4.6.1. Now I need to find out how the application configuration file has changed in v4.6.1 versus v4.0.