It seems that some builds of older versions were re-triggered on Jitpack and errored out:
https://jitpack.io/com/github/KeepSafe/TapTargetView/1.9.1/build.log
⚠️ ERROR: No build artifacts found
Unfortunately, this breaks Gradle builds for any projects that depend on these older versions. A recent example is the icon pack library Candybar (see zixpo/candybar#209). Would it by chance be possible to trigger older version builds, so these versions become available on Jitpack again?
