Fixing Alias Error

For some time I get this error: “Not unique table/alias: ‘adm_invoice_hdr’”
After some research I’ve found it might be caused by identical table prefixes. I have two sets of table to generate invoices (in this case Incoive Headers). They have different names, but pretty much identical structures, which I thought should be enough for SC to recognize the difference.
The wirdest part is that this error pops-up when I open the project Menu. there is no code of any kind referencing any of these tables, so I can’'t understand where SC gets this ifnormation from.

I kinda suspect , that the culprit is in SC Dictionary, but would love to hear your opinions,…
Thanks.