Veteran app developers of the jailbreak community have recently unleashed the modded version of Cydia Extender for jailbroken iOS 10 devices, which enabled the use of free Apple IDs to overcome the 7-day signing limitation of Yalu102 jailbreak. However, the modded version brings its own share of inherent bugs such as missing packages or directory path when using it to install the Yalu102 jailbreaking app.
Newcomers to iOS jailbreaking scene can now follow a simple troubleshooting guide to resolve the missing directory/package issue, with due credit to folks at Redmond Pie:
Step 1: Ensure that you have installed a terminal app such as MTerminal on the affected iOS device. If not, open Cydia and browse for MTerminal app, and then install it.
Step 2: Launch the MTerminal app on your iPhone or iPad and then you can unlock root access by typing in "su" and hitting the enter key on your device. If you are prompted for the password, just enter "alpine".
Step 3: After entering the password, you will attain super-user privilege for your account. Then type in the following command and hit enter:
mkdir /var/log/apt
Step 4: Now enter another command to resolve the second error:
mkdir -p var/cache/apt/archives/partial
That's it. You should no longer see the two problematic error messages in Cydia Extender.
[Source: Redmond Pie]