[SC 8.2u1] FieldInspector - cannot inspect field name

[alan-null]

Steps to Reproduce the Problem

1. Open Content Editor
2. Click on any field title

Expected Behavior

You should see field name and field title if you click on it again

Actual Behavior

Nothing happens
Errors:

HttpRequest.ts:25GET http://domain/sitecore/admin/dbbrowser.aspx?db=master&lang=en&id=undefined 500 (Internal Server Error)HttpRequest.execute @ HttpRequest.ts:25FieldInspectorModule.getFieldName @ FieldInspectorModule.ts:252FieldInspectorModule.writeDownFieldName @ FieldInspectorModule.ts:196(anonymous function) @ FieldInspectorModule.ts:154(anonymous function) @ FieldInspectorModule.ts:301
jsnlog.min.js:1 : {"stack":"Script error. \n at :undefined:undefined","message":"Script error.","logData":"Script error."}i.cerror @ jsnlog.min.js:1i.sendLogItemsConsole @ jsnlog.min.js:1i.sendBatch @ jsnlog.min.js:1i.log @ jsnlog.min.js:1n.log @ jsnlog.min.js:1n.fatalException @ jsnlog.min.js:1__jsnlog_configure.function.window.onerror @ jsnlog.min.js:1
FieldInspectorModule.ts:249Uncaught TypeError: Cannot read property 'innerText' of undefined(…)

Specifications

Sitecore version: 8.2u1