[Nokia 3 Guides, News, & Discussion] bigrammy:
OK I think I understand your problem. :eek:

Generally you cannot update via OTA due to the fact that OEM's generally use "Patch" ROM's rather than "Unconditional Block" update's.

A Patch ROM will fail If anything has been modified in the original STOCK ROM this is because it patches existing files rather than simply replacing them as in a Unconditional Block update. Patch ROM's are used to keep the download size to a minimum so unless you got a full STOCK TWRP backup of your /boot /recovery and /system prior to making any modification your likely to be out of luck. :(

If you check inside the official OTA's you will see a file called system.patch.dat if this file size is anything other than 0 that means it's a patch ROM which will require full stock unmodified ROM to work the system.transfer.list is where all the magic happens and if you open it in a good text editor you will see all the patching and checks that take place using things like "bsdiff" "imgdiff" etc etc these are not plain english but are all numerical hashes here is a small excerpt :eek:

"system.transfer.list excerpt"

4
797319
205
22442
erase 1160,335098,359936,369652,369653,383891,383892,387758,387759,390194,390195,390346,390347,390359,390360,390361,390362,390363,390364,390365,390366,390405,390406,390469,390470,390564,390565,390657,390658,390688,390689,390892,390893,391048,391049,391279,391280,391285,391286,391294,391295,391318,391319,391327,391328,391331,391332,391338,391339,391513,391514,391515,391516,391521,391522,391529,391530,391535,391536,391541,391542,391555,391556,391562,391563,391580,391581,391582,391583,391588,391589,391602,391603,391610,391611,391614,391615,391697,391698,391747,391748,391761,391762,391780,391781,391791,391792,391803,391804,391805,391806,391870,391871,391936,391937,391946,391947,392013,392014,392016,392017,392018,392019,392030,392031,392035,392036,392098,392099,392129,392130,392347,392348,392349,392350,392351,392352,392353,392354,392355,392356,392357,392358,392363,392364,392447,392448,392452,392453,392454,392455,392542,392543,392630,392631,392636,392637,392642,392643,392648,392649,392654,392655,392656,392657,392660,392661,392662,392663,392664,392665,392666,392667,392668,392669,392671,392672,392673,392674,392675,392676,392677,392678,392679,392680,392681,392682,392683,392684,392685,392686,392687,392688,392689,392690,392691,392692,392693,392694,392695,392696,392697,392698,392699,392700,392701,392702,392703,392704,501064,501065,501074,501075,501089,501090,501099,501100,501110,501111,501155,501156,501175,501176,501188,501189,501271,501272,501303,501304,501314,501315,501327,501328,501338,501339,501350,501351,501360,501361,501395,501396,501485,501486,501496,501497,501498,501499,501572,501573,501632,501633,501757,501758,501767,501768,501789,501790,501799,501800,501809,501810,501832,501833,501843,501844,501851,501852,501858,501859,502120,502121,502179,502180,502198,502199,502208,502209,502230,502231,502247,502248,502258,502259,502270,502271,502324,502325,502346,502347,502360,502361,502458,502459,502497,502498,502510,502511,510173,510174,510187,510188,510199,510200,510213,510214,510224,510225,510266,510267,510374,510375,511431,511432,511443,511444,511445,511446,511447,511448,511449,511450,511451,511452,511453,511454,511455,511456,511457,511458,511459,511460,511461,511462,511463,511464,511465,511466,511467,511468,511469,511470,511471,511472,511473,511474,511476,511477,511478,511479,511480,511481,511482,511483,511508,511509,511510,511511,511519,511520,511525,511526,511535,511536,511542,511543,511568,511569,511573,511574,511996,511997,512003,512004,512008,512009,512013,512014,512018,512019,512023,512024,512050,512051,512056,512057,512112,512113,512122,512123,512140,512141,512158,512159,515068,515069,515080,515081,515086,515087,515092,515093,515104,515105,515221,515222,515261,515262,515320,515321,515382,515383,515562,515563,515569,515570,515591,515592,515842,515843,515887,515888,515940,515941,516711,516712,518155,518156,518164,518165,518173,518174,518264,518265,518288,518289,518293,518294,518447,518448,518469,518470,518509,518510,518516,518517,518525,518526,518541,518542,518553,518554,518666,518667,518722,518723,518729,518730,518820,518821,519016,519017,519046,519047,519084,519085,519122,519123,519264,519265,519457,519458,519496,519497,519520,519521,519583,519584,519594,519595,519773,519774,519780,519781,519986,519987,520074,520075,520167,520168,520468,520469,520556,520557,520567,520568,520745,520746,520816,520817,520842,520843,520850,520851,520855,520856,520994,520995,521023,521024,521033,521034,521040,521041,521100,521101,521143,521144,521167,521168,521179,521180,521185,521186,521194,521195,521201,521202,521208,521209,521255,521256,521291,521292,521297,521298,521376,521377,521488,521489,521496,521497,521504,521505,521619,521620,521624,521625,521633,521634,521742,521743,521882,521883,522274,522275,522551,522552,522560,522561,522577,522578,522613,522614,522685,522686,522700,522701,522705,522706,522720,522721,522762,522763,522805,522806,522834,522835,522839,522840,522900,522901,522935,522936,522949,522950,522955,522956,522979,522980,522996,522997,523009,523010,523034,523035,523068,523069,523078,523079,523312,523313,523397,523398,523405,523406,523422,523423,523430,523431,523439,523440,523459,523460,523636,523637,523642,523643,523654,523655,523659,523660,523685,523686,523701,523702,523728,523729,523735,523736,523760,523761,523766,523767,558574,558575,559784,559785,560952,560953,561124,561125,561136,561137,561149,561150,561170,561171,561185,561186,561219,561220,561238,561239,561264,561265,561270,561271,561275,561276,562539,562540,562546,562547,562574,562575,562580,562581,562669,562670,562681,562682,562698,562699,562715,562716,562723,562724,562848,562849,562894,562895,563467,563468,563484,563485,563494,563495,563499,563500,563538,563539,563543,563544,563586,563587,563639,563640,563744,563745,563858,563859,563889,563890,563910,563911,563946,563947,564033,564034,564119,564120,564161,564162,564169,564170,564179,564180,564301,564302,564323,564324,564355,564356,564386,564387,564428,564429,564438,564439,564446,564447,564455,564456,564556,564557,564680,564681,564767,564768,564774,564775,564781,564782,564863,564864,564868,564869,564875,564876,564880,564881,564891,564892,564900,564901,564908,564909,564915,564916,564928,564929,564959,564960,564982,564983,564989,564990,565015,565016,565195,565196,565227,565228,565251,565252,565453,565454,565459,565460,565465,565466,565499,565500,565548,565549,565555,565556,565747,565748,565772,565773,565774,565775,565782,565783,565801,565802,565807,565808,565812,565813,565818,565819,565829,565830,565835,565836,565838,565839,565840,565841,565842,565843,565844,565845,565877,565878,565879,565880,565888,565889,565892,565893,565902,565903,565909,565910,565943,565944,565947,565948,565952,565953,565955,565956,565958,565959,565961,565962,565964,565965,565999,566000,566004,566005,566086,566087,566097,566098,566120,566121,566143,566144,570659,570660,570663,570664,570667,570668,570680,570681,570872,570873,570927,570928,571007,571008,571089,571090,571412,571413,571418,571419,571446,571447,571867,571868,571928,571929,571997,571998,572002,572003,573105,573106,573142,573143,574989,574990,574996,574997,575006,575007,575037,575038,575040,575041,575283,575284,575313,575314,575323,575324,575341,575342,575354,575355,575492,575493,575571,575572,575577,575578,575701,575702,575970,575971,576036,576037,576102,576103,576328,576329,576577,576578,576648,576649,576681,576682,576772,576773,576782,576783,577025,577026,577120,577121,577220,577221,577533,577534,577567,577568,577841,577842,577873,577874,577880,577881,577884,577885,577890,577891,577893,577894,578087,578088,578128,578129,578141,578142,578147,578148,578160,578161,578218,578219,578257,578258,578270,578271,578275,578276,578284,578285,578291,578292,578302,578303,578307,578308,578367,578368,578388,578389,578394,578395,578441,578442,578672,578673,578676,578677,578774,578775,578889,578890,578945,578946,578952,578953,578959,578960,579123,579124,579127,579128,579136,579137,579251,579252,579256,579257,579465,579466,580023,580024,580405,580406,580415,580416,580436,580437,580483,580484,580579,580580,580597,580598,580601,580602,580621,580622,580696,580697,580758,580759,580802,580803,580806,580807,580809,580810,580869,580870,580917,580918,580935,580936,580940,580941,580971,580972,580989,580990,580994,580995,581009,581010,581048,581049,581104,581105,581114,581115,581465,581466,581588,581589,581611,581612,581636,581637,581641,581642,581653,581654,581657,581658,581695,581696,581727,581728,581732,581733,581766,581767,581771,581772,581781,581782,581793,581794,581806,581807,581810,581811,581823,581824,581830,581831,581845,581846,581889,581890,581893,581894,581923,581924,581997,581998,582613,582614,582650,582651,583276,583277,584000,584001,584059,584060,584124,584125,584139,584140,584217,584218,586291,586292,586295,586296,586324,586325,586335,586336,587576,587577,587588,587589,587637,587638,587690,587691,587693,587694,587700,587701,587704,587705,587708,587709,587952,587953,587989,587990,588011,588012,588015,588016,588035,588036,588047,588048,588077,588078,588081,588082,588100,588101,588150,588151,588174,588175,588209,588210,588214,588215,588217,588218,628665,654848
move fe3c6b9a98448e2a646608a28ced604e26b6a0a5 2,541661,541662 1 2,490906,490907
move 7652ac0b93db9b8799dace2fd94d3d28f1bc75bb 2,1012375,1012477 102 2,1001759,1001861
move fe3c6b9a98448e2a646608a28ced604e26b6a0a5 2,458745,458746 1 2,490892,490893
move 48c5b2a1af90d555593fd4d61ff4ce70c59513ba 2,444063,454506 10443 2,282410,292853
bsdiff 0 177 fe1bb206c8dff871e3241d50766bbaced412ba9a 704186eda2e29d3ac98e7d2ce13d183205306839 2,541671,541732 61 2,490916,490977
imgdiff 177 2029 ad9c574938b2475294b9e70c766d371c4a85f078 b4ea6da34967d3db0f0a9ad1606b552f07b00f31 2,936841,936849 8 2,925103,925111
move 50e352fec39c29cbfd5918fe0fa66d8c3e2443ce 2,1011565,1011578 13 2,1000949,1000962
imgdiff 2206 2029 07d236d308437a710208026938e0449357bf659c 2ed96648425f6745050c23c6cf49de84f0dda762 2,941372,941384 12 2,930740,930752
move 9b57941ba400b0f52fa44572e242294d5b175189 2,1010719,1010723 4 2,1000103,1000107
move d3ef44ed506507859212bd3c81dd6daf94acb100 2,1011547,1011554 7 2,1000931,1000938
move e2f4dd657fe7e364d665e3a5424b9c830ddaf488 2,884730,884731 1 2,786408,786409
bsdiff 4235 376 28080c040b7e7803c90acf90b51ab968a8f771d3 64b22137fb83ce48efa9e2ca607a038f334c81a3 2,1011180,1011183 3 2,1000564,1000567
move cca6e19287533d408d949b0645a06cbdca013e15 2,1012637,1012639 2 2,1002021,1002023
imgdiff 4611 2032 4c3df98ed1f55965f8d1c2d4c2909ea538eea5a1 3d90bd5180d67dfa153b9c4795849fcec511d662 2,941788,941792 4 2,931154,931158
move 5d5250800a84086cec877ec50ba2d5f7bbb17eaf 2,458721,458722 1 2,490433,490434
move 147c6c8a6e257bba1b826b3fca6d741086a9aee1 2,1010415,1010420 5 2,999799,999804
move 2e7fa23caebf343232415108b559918732b1d26c 2,1011344,1011359 15 2,1000728,1000743
move 46e64cbe4c2d685ca8e5c815758ac5bed10b64da 2,1015594,1015598 4 2,1009706,1009710
bsdiff 6643 4486 0fcb13f3e3cb4567a99f5eaa398cc2ec3ef6d0e0 1ddbbfd12aeb751ab9c99babc3e5536bb5d465e6 2,1010724,1010778 54 2,1000108,1000162
imgdiff 11129 3395 ed20e76ef0ae4ffa6addb3962eb1e4673330d063 1d9c42d600f7a58ab5f172fc86dd59e814966a49 2,941765,941767 1 2,931132,931133
imgdiff 14524 2020 2c99ff0eb933d6b88c3d25692f97b0a85b7b7ad9 aa1a549771c5da848a5510d22d5c2375f6b2b724 2,942509,942511 2 2,931875,931877
imgdiff 16544 2032 03d3cfff91935ef934d08547b5b14e356ae8093b 36ba3c7e7479fa011e50476bd1479ca11f3f1c49 2,941665,941672 7 2,931032,931039
imgdiff 18576 2016 c746c5913ed1bdfa84532bb3aa6d0a83124fcf8b d2a33ec55c747d57f468f193bb514c83facf7b38 2,936823,936831 8 2,925085,925093
bsdiff 20592 176 363b2c991637b72750954fe128524c2f3cbc1365 ffe838f427e2072915a68c7cb9cedaa58ad08c7a 2,542204,542256 52 2,491449,491501
move cd568405687e26ce60382c52ce470b3c4d081876 2,1010937,1010979 42 2,1000321,1000363
bsdiff 20768 246 485c4614e2d0a89a4f917c7423910e09237a1a06 69f6ec80695f18ea87548928031ac1a0ef4dce70 2,1010705,1010718 13 2,1000089,1000102
imgdiff 21014 240182 9d9a05fc727779e61c9492263f135c120e41f01d 7ba5e7b57ec388e7a2a60b3497518db8a3596d32 2,940864,941294 401 2,930281,930682
move e5ff505881afd8e5aaff0a12f22c22e6b1621c3e 2,1010429,1010454 25 2,999813,999838

So do you have a Stock Rom backup of 7.0 :confused: