Error on running Microbiome package on my imported data

I am trying to use a BioManager package called Microbiome to determine alpha diversity in my data (mydata1). However I do get an error. This is shown below:
`> mydata1
Species
1 Streptococcus
2 Mycobacterium
3 Atopobium
4 Granulicatella
5 Actinomyces
6 Catonella
7 Homo
8 Macaca
9 unclassified (derived from Bacteria)
10 Eubacterium
11 Clostridium
12 Gemella
13 Lactobacillus
14 Sorghum
15 Rothia
16 Bifidobacterium
17 unclassified (derived from Clostridiales)
18 Bacillus
19 Canis
20 Ruminococcus
21 Schistosoma
22 Enterococcus
23 Danio
24 Neisseria
25 Pan
26 Lactococcus
27 unclassified (derived from Siphoviridae)
28 Staphylococcus
29 unclassified (derived from Clostridiales Family XI. Incertae Sedis)
30 Ciona
31 Mobiluncus
32 Veillonella
33 Prevotella
34 Peptostreptococcus
35 Olsenella
36 Loa
37 Nonionella
38 Oribacterium
39 Oryza
40 Shuttleworthia
41 Fusobacterium
42 Rattus
43 Moniezia
44 Collinsella
45 unclassified (derived from Erysipelotrichaceae)
46 Bacteroides
47 Xylosandrus
48 Slackia
49 Coprococcus
50 Pongo
Abundance
1 46927
2 11077
3 8951
4 4685
5 4016
6 1904
7 1000
8 688
9 568
10 530
11 259
12 253
13 124
14 115
15 112
16 99
17 85
18 81
19 81
20 80
21 80
22 77
23 72
24 67
25 64
26 62
27 62
28 61
29 58
30 56
31 54
32 54
33 45
34 44
35 41
36 39
37 38
38 37
39 34
40 33
41 32
42 32
43 31
44 27
45 27
46 24
47 23
48 22
49 22
50 22``

Dat1 <-microbiome::alpha(mydata1, index = "all")
Observed richness
Other forms of richness
Diversity
Error in sum(x) : invalid 'type' (character) of argument
kable(head(tab))
Error in head(tab) : object 'tab' not found
Dat1
Error: object 'Dat1' not found
Dat1 <-microbiome::alpha(mydata1, index = "all")
Observed richness
Other forms of richness
Diversity
Error in sum(x) : invalid 'type' (character) of argument

What could be accounting for this error please? Is the problem with the content of  my data or what? I will be happy to get your help. 
Regards,
J

The code for analysing the data was obtained from this website: https://microbiome.github.io/tutorials/Alphadiversity.html

The code from the site is as shown below:

library(microbiome)
library(knitr)
data(dietswap)

pseq <- dietswap
tab <-microbiome::alpha(pseq, index = "all")
kable(head(tab))

	observed	chao1	diversity_inverse_simpson	diversity_gini_simpson	diversity_shannon	diversity_fisher	diversity_coverage	evenness_camargo	evenness_pielou	evenness_simpson	evenness_evar	evenness_bulla	dominance_dbp	dominance_dmn	dominance_absolute	dominance_relative	dominance_simpson	dominance_core_abundance	dominance_gini	rarity_log_modulo_skewness	rarity_low_abundance	rarity_rare_abundance
Sample-1	104	114.6667	7.561722	0.8677550	2.940698	16.69360	4	0.2014036	0.6331719	0.0727089	0.1709714	0.3298916	0.3279347	0.4297198	2774	0.3279347	0.1322450	0.9276510	0.8625360	2.057691	0.0289632	0.0146589
Sample-2	110	121.6364	8.102943	0.8765881	2.822472	15.20257	3	0.2261992	0.6004646	0.0736631	0.1334372	0.2755652	0.2428626	0.4656170	5121	0.2428626	0.1234119	0.9330361	0.8843695	2.057552	0.0299725	0.0349047
Sample-3	103	107.5000	4.291085	0.7669587	2.407963	13.42077	2	0.2109176	0.5195476	0.0416610	0.1373098	0.2541325	0.4594744	0.5603989	13271	0.4594744	0.2330413	0.9514247	0.9083094	2.052324	0.0339646	0.0093134
Sample-4	105	112.1429	7.930799	0.8739093	2.992482	15.56061	4	0.3422309	0.6429969	0.0755314	0.1711334	0.3176017	0.3230653	0.3957720	4279	0.3230653	0.1260907	0.8621367	0.8569405	2.051175	0.0348056	0.0367686
Sample-5	103	110.6818	3.170738	0.6846160	2.106022	14.53671	1	0.1407817	0.4544002	0.0307839	0.1661081	0.2310307	0.5450144	0.6317579	9456	0.5450144	0.3153840	0.9535447	0.9212609	2.059634	0.0441499	0.0105476
Sample-6	105	113.9091	2.953753	0.6614476	2.071136	14.55619	1	0.1709221	0.4450266	0.0281310	0.1625409	0.2308364	0.5693811	0.6430163	11243	0.5693811	0.3385524	0.9258078	0.9192203	2.059421	0.0375772	0.0168642