Unable to downgrade certain package via Backend UI

[saschlong]

I tried to downgrade the package dc-general to the version 2.0.0.0-beta34, but when I try to set the exact version I'm only able to set it to 2.0.0.0-beta

I have to edit the composer.json to set the exact version, then it works.

//edit: The Contao-Version is 3.5.6

[xchs]

I'm facing the same problem with composer client version 0.16.6.

[backbone87]

as a workaround you can use export mode and edit the constraint manually