We updated to Visual Studio 17.3.4 and now all of our type script files are giving us intellisense errors. We can build without any errors but when we open any of our .ts files they show lots of errors that were not present before. It seems to no longer find any of the classes and interfaces in other files. We tried added a tsconfig.json file and that seemed to help some but we get a whole different set of errors from lib.dom.d.ts

"compileOnSave": true,
"compilerOptions": {
"noImplicitAny": false,
"noEmitOnError": true,
"removeComments": true,
"sourceMap": false,
"target": "es6",
"typeRoots": [ "/Scripts" ]
"exclude": [
"node_modules",
"wwwroot"

Severity Code Description Project File Line Suppression State
Error TS2687 (TS) All declarations of 'name' must have identical modifiers. C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\SixDisciplines.FrameworkAllegro.UI\tsconfig.json C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\packages\Microsoft.TypeScript.MSBuild.4.5.3\tools\tsc\lib.dom.d.ts 5074 Active
Error TS2687 (TS) All declarations of 'root' must have identical modifiers. C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\SixDisciplines.FrameworkAllegro.UI\tsconfig.json C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\packages\Microsoft.TypeScript.MSBuild.4.5.3\tools\tsc\lib.dom.d.ts 5075 Active
Error TS2320 (TS) Interface 'HTMLElement' cannot simultaneously extend types 'Element' and 'HTMLOrSVGElement'.
Named property 'blur' of types 'Element' and 'HTMLOrSVGElement' are not identical. C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\SixDisciplines.FrameworkAllegro.UI\tsconfig.json C:\SDBS_ROOT\SCS\Allegro\Main\FrameworkAllegro\packages\Microsoft.TypeScript.MSBuild.4.5.3\tools\tsc\lib.dom.d.ts 6132 Active

Hi @Dave Keck ,

Welcome to Microsoft Q&A forum.

For Error TS2687, Are there some name conflicts maybe? Please check and compare this file: TypeScript – lib.dom.d.ts . For Error TS2320, did you make your own element interface with blur property?

Besides, in case this is a potential issue caused by updating Visual Studio to 17.3.4, I recommend also reporting this issue on our Developer Community for further investigate.

Best Regards,
Tianyu

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