cannot read fasta alignment file

[wowfee]

Hello, After ggmsa is installed successfully, I read in the sequence using the following code:

library(ggmsa)
protein_sequences <- system.file("extdata","test.fasta",package="ggmsa")

nor errors,but i think it not read fasta file,cause :
protein_sequences [1]""
nothings in protein_sequences, and my fasta file format is :

>AF178440.1/5925-6123
UUGACUAUGUGAUCUUGCUUUCG...
>AB017037.1/6286-6484
GAAAAUGUGUGAUCUGAUUAGAA...
>AF014388.1/6078-6278
GUUAAGAUGUGAUCUUGCUUCCU...
>AF218039.1/6028-6228
GCAAAAAUGUGAUCUUGCUUGUA...
>AF183905.1/5647-5848
CCAACAAUGUGAUCUUGCUUGCG...
>AB006531.1/6003-6204
CUGACUAUGUGAUCUUAUUAAAA...
>AF022937.1/6935-7121
AGUGUUGUGUGAUCUUGCGCGAU...

all sequences are alingment and have same length. i wonder to know if there are any problem above ?
thanks

[orangeSi]

protein_sequences <- system.file("extdata","test.fasta",package="ggmsa") mean ggmsa_install_path/extdata/test.fasta, so can also set fasta path by protein_sequences <- "/xxx/xxx/test.fasta".
That confuse me a lot for R newbie!