Angular で開発時に DB から多めのデータを取得すると
ERR_CONTENT_LENGTH_MISMATCH でレスポンスコードは 200 なのに
データが表示できず何故に...、となった時の対応メモ。
どうも Angular のバージョンで挙動が変わるよう。
環境にも依存しそうな気がするのでご参考までに。

ERR_CONTENT_LENGTH_MISMATCH が出た Angular のバージョン

ng version
     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 10.0.3
Node: 12.14.0
OS: darwin x64

Angular: 10.0.4
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router
Ivy Workspace: Yes

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.1000.3
@angular-devkit/build-angular     0.1000.3
@angular-devkit/build-optimizer   0.1000.3
@angular-devkit/build-webpack     0.1000.3
@angular-devkit/core              10.0.3
@angular-devkit/schematics        10.0.3
@angular/cli                      10.0.3
@ngtools/webpack                  10.0.3
@schematics/angular               10.0.3
@schematics/update                0.1000.3
rxjs                              6.5.4
typescript                        3.9.7
webpack                           4.43.0

ERR_CONTENT_LENGTH_MISMATCH が出なくなった Angular のバージョン

ng version
     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 12.1.4
Node: 12.14.0
Package Manager: npm 7.20.6
OS: darwin x64

Angular: 12.1.4
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1201.4
@angular-devkit/build-angular   12.1.4
@angular-devkit/core            12.1.4
@angular-devkit/schematics      12.1.4
@schematics/angular             12.1.4
rxjs                            6.6.7
typescript                      4.3.5