Comment 2 for bug 1676164

Not because of the enterprise argument, but because Xul support will be dropped in 57.x. This means a large number of vital extensions will cease to work.

Before switching Zesty over to 56.x, please consider adding 52-ESR for Zesty users. Come release 56.x profiles will no longer migrate correctly if one decides to downgrade.

Detailed information available here: https://github.com/Aris-t2/ClassicThemeRestorer/issues/299