Invalid Archive error

[Kinchul]

I am unable to install the ArduCAM_ESP8266_UNO board manager in the Arduino IDE.

I added the .json link to the Additional Boards Manager URLs in preferences.

When I try to install it, it downloads correctly until the end of tools/ and then throw this error:

Invalid archive: it must contain a single root folder while file variants/ is outside tools/
java.lang.RuntimeException: java.io.IOException: Invalid archive: it must contain a single root folder while file variants/ is outside tools/
	at cc.arduino.contributions.packages.ui.ContributionManagerUI.lambda$onInstallPressed$2(ContributionManagerUI.java:179)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: Invalid archive: it must contain a single root folder while file variants/ is outside tools/
	at cc.arduino.utils.ArchiveExtractor.extract(ArchiveExtractor.java:180)
	at cc.arduino.utils.ArchiveExtractor.extract(ArchiveExtractor.java:82)
	at cc.arduino.contributions.packages.ContributionInstaller.install(ContributionInstaller.java:162)
	at cc.arduino.contributions.packages.ui.ContributionManagerUI.lambda$onInstallPressed$2(ContributionManagerUI.java:172)
	... 1 more

The installation stops and I end up with an incomplete package that apperears "installed", but no board shows in the dropdown menu.

I have the same issue on two different computers.

Using a fresh install of Arduino IDE 1.8.15. I am not using the Arduino IDE from the Windows 10 store.