Typescript issues after VS2015 CTP6

Today my machine just woke up, with Typescript compilation error.
I get things like:

Error    2   The specified task executable location "C:\Program Files (x86)\Microsoft SDKs\TypeScript\tsc.exe" is invalid.   UpgradeHelpers.WebMap.Client


Error    1   Your project file uses a different version of the TypeScript compiler and tools than is currently installed on this machine.  No compiler was found at C:\Program Files (x86)\Microsoft SDKs\TypeScript\tsc.exe.  You may be able to fix this problem by changing the <TypeScriptToolsVersion> element in your project file.    UpgradeHelpers.WebMap.Client

All this seems to be related to installing VS 2015 Preview CTP6.
Also Typescript compilation in VS2013 stopped working.

The workaround is:

Run Repair for TypeScript 1.4 from Control Panel/Uninstall Programs.

You can find more details in