Cannot run `apt update` "At least one invalid signature was encountered"
5316
Update from 14.04 to 16.04 failed with GPG error
117852
"Package dependencies cannot be resolved" error when installing software
135985
Apt-get saying "Unable to correct problems, you have held broken packages."
28247
Google Chrome PPA upgrade invalid signature
4248
How to fix apt: Signature by key uses weak digest algorithm (SHA1)?
90937
apt-get update errors
135575
How to fix a "Failed to fetch binary-armhf/Packages" error during apt-get update?
122742
Why does apt-get install a newer dependency than supported by the specified package
49149
How do I solve "Unable to fetch some archives, maybe run apt-get update or try with --fix-missing" error?
93942
How to fix "Failed to download repository information" error while updating?
127196
"Error processing package" - apt upgrade cannot run due to package configuration errors
96696
timeout errors in apt-get update/install
23819
"GPG error: Release: The following signatures were invalid: BADSIG"
32220
How to resolve Unmet dependencies error?
65099
Unable to install any updates through update manager/apt-get upgrade
30754
Cannot update: "No available releases found"
107340
"Invalid signature file" when attempting to run a .jar