Problem phenomenon 1:
Local install option is grayed out and cannot be clicked.
Solutions:
1. Clear system update application data, setting path: Settings > Apps > App Management > Three dots on upper right corner > Show system > Software update > Storage usage > clear data.
2. Turn off the phone's Wi-Fi and mobile network.
3. Re-enter the system update page.
Problem phenomenon 2:
The installation rollback package displays "Decompression failed, installation package mismatch" or "Verification failed, error reading file"
Note: Before troubleshooting, please confirm that the rollback package is downloaded from the official link and the model corresponds
（For example, the Master Explorer Edition cannot use the Master Edition package and the model & the package must correspond）
Rolling back a major version will clear all data, please back up before rolling back.
After you have backed up your data, perform the correct rollback as follows:
1. Move the downloaded rollback package to the phone storage directory
Rollback package download：
Open the community post to find and open the link of the rollback package, the download time is long, please keep the network smooth.
Directly click the link of the rollback package in the official website community, Google chrome starts to download.
2. Turn on local installation option
Setting path: Settings > About device > Version > Click on the Build number 7 times > open developer options.
Note: If you don't turn on the developer options, you will not find the local install option in the next step.
3. Install the rollback package
a. Settings > About device > Click the top version information > Three dots in the upper right corner> Local install, enter the phone storage
b. Click the menu bar in the upper left corner> select the phone model and find the rollback package in the phone storage (phone root directory)
c. Click on the rollback package, the system prompts Verifying, and after the verification is completed (it is expected to take more than 1 minute), the system pops up the installation interface, click Install, the phone will be turned off, and the rollback will be successful. After the system installation is completed, the system is automatically turned on. (The system installation time is expected to take more than 5 minutes. Please do not perform any operations on the phone.)
If the above methods do not solve your problem, please back up your data and visit the nearest authorized realme service center for testing.