Thank you for your help with this : )
Both seem to have the standard unix LF - if I have understood CRLF status correctly - and are tab-deliminated. Do the same endings appear on your machine?
(hmmerEnv) u1983390@vettel:Mimps$ cat -te F._oxysporum_f._sp._cubense_UK0001.fna_mimp_hits.gff | head
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16238^I21460^I.^I+^I.^ISHORT_ID=mimp_region1;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16239^I21460^I.^I-^I.^ISHORT_ID=mimp_region2;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16537^I21612^I.^I+^I.^ISHORT_ID=mimp_region3;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16546^I21613^I.^I-^I.^ISHORT_ID=mimp_region4;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16868^I21890^I.^I+^I.^ISHORT_ID=mimp_region5;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I16869^I21890^I.^I-^I.^ISHORT_ID=mimp_region6;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I93675^I98697^I.^I-^I.^ISHORT_ID=mimp_region7;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I93675^I98696^I.^I+^I.^ISHORT_ID=mimp_region8;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I93951^I99018^I.^I+^I.^ISHORT_ID=mimp_region9;^IID=.;$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^Ibed2gff^Imimp_region^I93952^I99027^I.^I-^I.^ISHORT_ID=mimp_region10;^IID=.;$
(hmmerEnv) u1983390@vettel:Mimps$ cat -te ../Index/F._oxysporum_f._sp._cubense_UK0001.fna.fai
VMNF01000001.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_1,_whole_genome_shotgun_sequence^I44428^I119^I80^I81$
VMNF01000010.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_10,_whole_genome_shotgun_sequence^I34672^I45223^I80^I81$
VMNF01000011.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_11,_whole_genome_shotgun_sequence^I3303011^I80449^I80^I81$
VMNF01000012.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_12,_whole_genome_shotgun_sequence^I3488972^I3424868^I80^I81$
VMNF01000013.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_13,_whole_genome_shotgun_sequence^I1244651^I6957573^I80^I81$
VMNF01000014.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_14,_whole_genome_shotgun_sequence^I3744637^I8217903^I80^I81$
VMNF01000015.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_15,_whole_genome_shotgun_sequence^I2630465^I12009468^I80^I81$
VMNF01000002.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_2,_whole_genome_shotgun_sequence^I115573^I14672933^I80^I81$
VMNF01000003.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_3,_whole_genome_shotgun_sequence^I4819209^I14790070^I80^I81$
VMNF01000004.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_4,_whole_genome_shotgun_sequence^I5233353^I19669639^I80^I81$
VMNF01000005.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_5,_whole_genome_shotgun_sequence^I5758795^I24968528^I80^I81$
VMNF01000006.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_6,_whole_genome_shotgun_sequence^I4265398^I30799427^I80^I81$
VMNF01000007.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_7,_whole_genome_shotgun_sequence^I6580744^I35118262^I80^I81$
VMNF01000008.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_8,_whole_genome_shotgun_sequence^I2830195^I41781385^I80^I81$
VMNF01000009.1_Fusarium_oxysporum_f._sp._cubense_strain_TR4_isolate_UK0001_scf_28419_9,_whole_genome_shotgun_sequence^I4494293^I44647077^I80^I81$