Blast Error: Tax database file not found

Hello, I am running this command for a blast search.

blastx -query Ndiv_cap300.fasta -out Ndiv_run -outfmt 7 -db nr -num_threads 32 -evalue 1e-3 -max_target_seqs 5

however I get the following error that I just do not understand

/Liams_Work$ blastx -query Ndiv_cap300.fasta -out Ndiv_run -outfmt 7 -db nr -num_threads 32 -evalue 1e-3 -max_target_seqs 5
terminate called after throwing an instance of 'ncbi::CSeqDBException'
  what():  NCBI C++ Exception:
    "/build/buildd/ncbi-blast+-2.2.28/c++/src/objtools/blast/seqdb_reader/seqdbtax.cpp", line 82: Error: ncbi::CSeqDBTaxInfo::x_Init() - Error: Tax database file not found.

any help would be greatly aprreciated.

Thanks in advance!