If you're saving to our public library, it must have a different number tied to it. For instance, if we have five blocks in one category, your block should be Block Name #6.

Solution:

In our public library of blocks, our naming conventions are set by numbers. For instance, if we have five Sponsor blocks in that particular category, they would be labeled Sponsor Block #1, Sponsor Block #2, etc)

If you’re trying to save a public block and it has the same naming convention as one that’s already public, it will not pass the validation check. To resolve this issue, simply click the block that you’re trying to save. Once you’re in the block, click the save icon that will open up the sharing and saving page. When prompted, rename your block to one that’s not current.