I can confirm this behavior. A document created with the previous beta version now results in a segfault of publisher when loading the document.
I'll attach the section from the problem report for the crashed application thread, maybe it helps identifying the cause:
Crashed Thread: 6 Dispatch queue: com.apple.root.utility-qos
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000008
Exception Note: EXC_CORPSE_NOTIFY
Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [0]
VM Regions Near 0x8:
-->
__TEXT 0000000100eff000-0000000100f81000 [ 520K] r-x/rwx SM=COW /Applications/Affinity Publisher Beta.app/
Thread 6 Crashed:: Dispatch queue: com.apple.root.utility-qos
0 liblibraster.dylib 0x000000010640ce59 Raster::DynamicBitmap::GetBackingData() const + 9
1 liblibpersona.dylib 0x000000011e930295 ImageNode::Load(Kernel::InSerialiser const&, Kernel::FileStore&, unsigned short) + 1221
2 liblibkernel.dylib 0x0000000106211c84 Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1284
3 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
4 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
5 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
6 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
7 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
8 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
9 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
10 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
11 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
12 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
13 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
14 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
15 liblibkernel.dylib 0x000000010621246b Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 59
16 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
17 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
18 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
19 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
20 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
21 liblibkernel.dylib 0x000000010621246b Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 59
22 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
23 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
24 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
25 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
26 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
27 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
28 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
29 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
30 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
31 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
32 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
33 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
34 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
35 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
36 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
37 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
38 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
39 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
40 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
41 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
42 liblibkernel.dylib 0x000000010621246b Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 59
43 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
44 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
45 liblibkernel.dylib 0x000000010621246b Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 59
46 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
47 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
48 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
49 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
50 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
51 liblibkernel.dylib 0x000000010621246b Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 59
52 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
53 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
54 liblibkernel.dylib 0x0000000106212666 Kernel::InSerialiserLoader::CompletePropertyObjects(Kernel::InSerialiserProperty&, unsigned int) + 566
55 liblibkernel.dylib 0x0000000106215039 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6697
56 liblibkernel.dylib 0x0000000106211c5c Kernel::InSerialiserLoader::LoadObject(Kernel::InSerialiserLoader::ObjectRec&) + 1244
57 liblibkernel.dylib 0x0000000106211650 Kernel::InSerialiserLoader::CompletePropertyObject(Kernel::InSerialiserProperty&) + 32
58 liblibkernel.dylib 0x0000000106214e23 Kernel::InSerialiser::ParseProperties(Kernel::InSerialiserLoader&) + 6163
59 liblibkernel.dylib 0x000000010621d148 Kernel::InSerialiserFile::ParseI(Kernel::InStream&, Kernel::FileStore&, bool, bool) + 520
60 liblibkernel.dylib 0x000000010621d467 Kernel::InSerialiserFile::ParseWithChecks(Kernel::InStream&, Kernel::FileStore&, bool) + 23
61 liblibpersona.dylib 0x000000011dcb3274 DocumentController::Load(Kernel::InStream&, Kernel::FileStore&) + 36
62 liblibkernel.dylib 0x00000001061ddb69 Kernel::Archive::LoadFile(Kernel::StringT<Kernel::TEncUtf8> const&, Kernel::FileStoreItem&) + 185
63 liblibpersona.dylib 0x000000011dca0d85 DocumentController::LoadFromArchiveI(bool, OpenDocumentFailedNotification&, bool) + 165
64 liblibpersona.dylib 0x000000011dcb01cd DocumentController::CompleteLoadArchiveI(Kernel::Counted<LoadDocumentOptions const>, OpenDocumentFailedNotification&, bool, bool, bool, bool) + 45
65 liblibpersona.dylib 0x000000011dcabc5c DocumentController::LoadDocumentI(Kernel::StringT<Kernel::TEncUtf8> const&, bool, LoadDocumentMode, bool, bool, Kernel::Counted<LoadDocumentOptions const>, OpenDocumentFailedNotification&) + 15500
66 liblibpersona.dylib 0x000000011dca77d2 DocumentController::LoadDocument(Kernel::StringT<Kernel::TEncUtf8> const&, bool, bool, LoadDocumentMode, Kernel::Counted<LoadDocumentOptions const>, OpenDocumentFailedNotification&) + 114
67 liblibpersona.dylib 0x0000000113482bb4 LoadDocumentCommand::Do() + 276
68 liblibpersona.dylib 0x000000011dcfa0f3 PersonaController::StaticDoCommand(void*) + 67
69 libdispatch.dylib 0x00007fff6faebdb8 _dispatch_client_callout + 8
70 libdispatch.dylib 0x00007fff6faedb2c _dispatch_root_queue_drain + 902
71 libdispatch.dylib 0x00007fff6faed755 _dispatch_worker_thread3 + 101
72 libsystem_pthread.dylib 0x00007fff6fe3d169 _pthread_wqthread + 1387
73 libsystem_pthread.dylib 0x00007fff6fe3cbe9 start_wqthread + 13