Eliminate "Specified cast is not valid" error during compilation

Visual Studio 2017 15.3 and newer, Visual Assist build 2231 and newer

A problem in early versions of Visual Studio 2017, i.e. 15.1 and 15.2, sometimes causes errant "Specified cast is not valid" compilation errors when Visual Assist is installed. The problem does not occur with 15.3 and newer. If the problem resurfaces and you are directed by the support team at Whole Tomato Software, work around the compilation errors by preventing Visual Assist from being notified of changes to the open solution. If directed, disable notifications by modifying the registry:

HKCU\Software\Whole Tomato\Visual Assist X\VANet15\EnableVcProjectSync = 0

Restore value to 01 to restore default behavior.

Visual Studio 2017 15.2 and older, Visual Assist build 2223 and older

A problem in Visual Studio 2017 sometimes causes errant "Specified cast is not valid" compilation errors when Visual Assist is installed. Visual Assist can work around the problem, but several features in Visual Assist are adversely affected in the process.

The ability to work around the problem varies with the build of Visual Assist.

If the workaround is enabled in your build, Visual Studio 2017 no longer notifies Visual Assist of changes to the open solution. In turn, several features in Visual Assist are affected because Visual Assist is not notified of the addition to, or removal of, files in your solution or of changes to include directories in your solution. The affected features include Open Find in Solution (Shift+Alt+O), #include completion, Find References, Change Signature, Rename, Add Include, and include-file resolution. In order to use an affected feature on a file(s) that has been added to, and not on a file(s) that has been removed from, your solution since it was last opened, you must reopen your solution so Visual Assist can ascertain the proper state of the solution. Also, in order for Visual Assist to recognize changes to the include paths in your solution since the solution was last opened, you must reopen your solution.

Visual Assist build 2223

The workaround to avoid errant "Specified cast is not valid" compilation errors is enabled by default. If you wish to disable the workaround and risk the chance of the compilation errors, modify the registry:

HKCU\Software\Whole Tomato\Visual Assist X\VANet15\ForceVs2017ProjectSync = 01

Restore value to 00 to avoid the compilation errors.

Visual Assist builds 2208-2217

The workaround to avoid "Specified cast is not valid" compilation errors is always enabled.

Visual Assist build 2219, and builds 2210 and older

The workaround is not available. If you get errant "Specified cast is not valid" compilation errors, update to a newer build of Visual Assist.

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