I took a look at your system and indeed you have 49 SKU's. However I didn't see an issue adding one more extra SKU there manually.
Since you are using an import to achieve this there must be some additional SKU in the import either a variation parent SKU or a composite parent SKU along with a new child SKU.
Would it be possible for you to attach your import so that I may take a look?
Looking forward to hear from you soon!
I am trying to do an inventory import to update the product lines that i have with all of the additional extended properties and product descriptions required for Amazon. When running the import i get the following error in the log "Building internal table. You have reached the limit of 50 items available on the community plan." I only have 49 SKU's currently so cannot understand why i am receiving this error. Can anybody help please.