https://github.com/timbru31/SilkSpawners/blob/master/src/main/java/de/dustplanet/silkspawners/listeners/SilkSpawnersInventoryListener.java#L63

This line only checks if the clicked slot is of type RESULT. However, other types of inventories have a result slot as well, like furnaces and villager trading windows (any maybe other inventory types as well).

This currently prevents not only crafting of spawners, but also trading (with customly setup villager trades).

This should be fixed via 5107300

Can you verify and close?
(Dev builds are here: https://ci.dustplanet.de/job/SilkSpawners)

Sorry for the delay in fixing this :/

This should work fine now.