Hello sir,
Please follow below steps:
1. Uninstall current ERA Explorer
2. Disable your firewall and antivirus
3. Install latest ERA Explorer setup and start it.
4. Enable antivirus and add ffmpeg.exe, ERABuddy.exe to exception list if antivirus gives alert.
The above error is caused if your firewall or antivirus blocks the ERA Explorer supporting files. In above case, the antivirus has deleted the ffmpeg.exe file which is required by ERA Explorer for optimizing storage. Please disable the antivirus and try again.