Clicking on Memory stabilizer does nothing

Preplanned a memory path, and it will not allow me to click on the memory stabilizer to place a memory. Nothing happens when I do so. Tested putting down another fragment in the same spot (which it let me do) and the same result occurs for the memory stabilizer in the same location.

Happened to me today. For my case, I found that this was caused by the newly spawned memory next to my planned memory which couldn't be connected to one another.