@MusopiaApps
I too experienced this problem today, the app stuck at the splash screen. Force quitting and re-launching resulted in the same.
The workaround stated in this thread did work (delete and re-install).
However, in case it helps Musopia, I checked out my device logs from the Console, to see if anything obvious was being reported, that may or may not assist with debugging:
default 15:44:18.111176+0930 JustinGuitar : Will add backgroundTask with taskName: , expirationHandler: <NSMallocBlock: 0x2820801c0>
default 15:44:18.111232+0930 JustinGuitar : Created background task . Assertion will be assigned soon
default 15:44:18.111289+0930 JustinGuitar : Creating new assertion since assertion is nil
default 15:44:18.125370+0930 JustinGuitar : Created new assertion <BKSProcessAssertion: 0x28164e260>
default 15:44:18.125439+0930 JustinGuitar : Ending background task with UIBackgroundTaskIdentifier: 32
default 15:44:18.125559+0930 JustinGuitar : Ending task with identifier 32 and description: , _expireHandler: <NSMallocBlock: 0x282096f80>
default 15:44:18.125701+0930 JustinGuitar : Decrementing reference count for assertion used by background task with identifier 32:
default 15:44:18.125920+0930 JustinGuitar : Will invalidate assertion: <BKSProcessAssertion: 0x28164e260> for task identifier: 32
default 15:44:45.337227+0930 JustinGuitar : Will add backgroundTask with taskName: , expirationHandler: <NSMallocBlock: 0x28200ffc0>
default 15:44:45.338006+0930 JustinGuitar : Created background task . Assertion will be assigned soon
default 15:44:45.338124+0930 JustinGuitar : Creating new assertion since assertion is nil
default 15:44:45.338279+0930 JustinGuitar Connection 5: cleaning up
default 15:44:45.338351+0930 JustinGuitar [C5 C59B23B0-E769-4173-9F2B-E92D8A9DB836 Hostname#17615696:443 tcp, url hash: e179ec31, tls, definite, attribution: developer] cancel
default 15:44:45.338457+0930 JustinGuitar [C5 C59B23B0-E769-4173-9F2B-E92D8A9DB836 Hostname#17615696:443 tcp, url hash: e179ec31, tls, definite, attribution: developer] cancelled
[C5.1 7610A755-A316-4280-94DC-2A0CB65CFD3B 192.168.1.163:65266<->IPv4#0040b556:443]
Connected Path: satisfied (Path is satisfied), viable, interface: en0, ipv4, dns
Privacy Stance: Not Eligible
Duration: 240.302s, DNS @0.000s took 0.013s, TCP @0.014s took 0.047s, TLS 1.3 took 0.051s
bytes in/out: 4494/3672, packets in/out: 11/19, rtt: 0.039s, retransmitted bytes: 0, out-of-order bytes: 0
default 15:44:45.339787+0930 JustinGuitar nw_protocol_tcp_log_summary [C5.1:3]
[18D701FD-2581-47D4-A983-96A6662C6BE2 :65266<->:443]
Init: 1, Conn_Time: 47.033ms, SYNs: 1, WR_T: 0/0, RD_T: 0/0, TFO: 0/0/0, ECN: 0/0/0, TS: 1
rtt_cache: none, rtt_upd: 8, rtt: 39.625ms, rtt_var: 9.500ms rtt_nc: 39.625ms, rtt_var_nc: 9.500ms base rtt: 28ms
ACKs-compressed: 0, ACKs delayed: 0 delayed ACKs sent: 0
default 15:44:45.339947+0930 JustinGuitar nw_flow_disconnected [C5.1 IPv4#0040b556:443 cancelled channel-flow ((null))] Output protocol disconnected
default 15:44:45.340126+0930 JustinGuitar nw_connection_report_state_with_handler_on_nw_queue [C5] reporting state cancelled
default 15:44:45.340214+0930 JustinGuitar Connection 4: cleaning up
default 15:44:45.340276+0930 JustinGuitar [C4 E0D708A5-86AB-4CBD-A5E4-3F9A85C0EA3F Hostname#0ffcd1f1:443 tcp, url hash: 3c907dab, tls, definite, attribution: developer] cancel
default 15:44:45.340358+0930 JustinGuitar [C4 E0D708A5-86AB-4CBD-A5E4-3F9A85C0EA3F Hostname#0ffcd1f1:443 tcp, url hash: 3c907dab, tls, definite, attribution: developer] cancelled
[C4.1 E3B3B40E-492E-4D8F-9244-EE9567AB1B0C 192.168.1.163:65264<->IPv4#5dcd4a55:443]
Connected Path: satisfied (Path is satisfied), viable, interface: en0, ipv4, dns
Privacy Stance: Not Eligible
Duration: 240.316s, DNS @0.000s took 0.010s, TCP @0.011s took 0.018s, TLS 1.3 took 0.052s
bytes in/out: 6547/2697, packets in/out: 12/17, rtt: 0.019s, retransmitted bytes: 0, out-of-order bytes: 0
default 15:44:45.341665+0930 JustinGuitar : Created new assertion <BKSProcessAssertion: 0x28164d590>
default 15:44:45.341892+0930 JustinGuitar nw_protocol_tcp_log_summary [C4.1:3]
[CB86B0EF-D3B9-44F8-AB6D-12594A57B975 :65264<->:443]
Init: 1, Conn_Time: 17.881ms, SYNs: 1, WR_T: 0/0, RD_T: 0/0, TFO: 0/0/0, ECN: 0/0/0, TS: 1
rtt_cache: none, rtt_upd: 7, rtt: 19.812ms, rtt_var: 3.500ms rtt_nc: 19.812ms, rtt_var_nc: 3.500ms base rtt: 17ms
ACKs-compressed: 0, ACKs delayed: 0 delayed ACKs sent: 0
default 15:44:45.342220+0930 JustinGuitar nw_flow_disconnected [C4.1 IPv4#5dcd4a55:443 cancelled channel-flow ((null))] Output protocol disconnected
default 15:44:45.342904+0930 JustinGuitar nw_connection_report_state_with_handler_on_nw_queue [C4] reporting state cancelled
default 15:44:45.343060+0930 JustinGuitar Connection 4: done
default 15:44:45.343203+0930 JustinGuitar tcp_output [C5.1:3] flags=[F.] seq=2421633485, ack=2069567257, win=4096 state=FIN_WAIT_1 rcv_nxt=2069567257, snd_una=2421633422
default 15:44:45.343533+0930 JustinGuitar tcp_output [C4.1:3] flags=[F.] seq=2075772846, ack=4244396617, win=4096 state=FIN_WAIT_1 rcv_nxt=4244396617, snd_una=2075772783