jsonDecode gives invalid for a valid JSON string.

**Describe the bug**
This error occurs when the json string is long or nested levels are deep.

**Stacktrace**
Event specific.

**Expected behavior**
It should validate and give the map accordingly.

**Smartphone (please complete the following information):**
 - Device: Moto G5 Plus.
 - OS: Android 8.1.0
 - Version: API level 27

**Additional context**
None.
