Update to lineage-18.1-20210408-nightly-jfltexx-signed.zip failed

Expected Behavior

System-Update-Install for OTA update.

Current Behavior

Nightly downloads and verifies without errors, but pressing install throws an error "Install error". Also not able to export the zip file to storage after downloading.

Possible Solution

Steps to Reproduce

1. Select System-Update-Install
2. Try export the zip file to storage after downloading

/device jfltexx /version lineage-18.1 /date 2021-04-08 /kernel /baseband /mods MindTheGapps

I have read the directions.