I have same issue when loading mission in multiplayer.
Here output from debugger:
STACK_TEXT:
WARNING: Frame IP not in any known module. Following frames may be wrong.
00b9d968 00e80f4f 62631f00 62631f00 62631f00 0x2e5ff001
00b9d978 00e813d8 00000005 00cef93a 00000001 arma3!simul::base::GetRTTITypeInfo+0x2e50f
00b9d980 00cef93a 00000001 0109b938 366ad900 arma3!simul::base::GetRTTITypeInfo+0x2e998
00b9d988 0109b938 366ad900 366ad900 ffffffff arma3!simul::base::Referenced::intrusive_ptr_release+0x247a
00b9d9b8 010f5162 00000001 0000007d 00000000 arma3!simul::sky::BaseKeyframe::SetInt+0x1fbd8
00b9d9dc 010648ce 35fcc418 000003b3 361be080 arma3!simul::clouds::CellularCloudGrid::GetWrap+0x2822
00b9da08 01106125 010f5120 361be080 1514ca80 arma3!simul::sky::BaseSky::GetAtmosphereThickness+0x1b24e
00b9daa4 01a088a9 0699605c 00b9e184 069af2d4 arma3!simul::clouds::CellularCloudGrid::GetWrap+0x137e5
00000000 00000000 00000000 00000000 00000000 arma3!simul::clouds::CloudGeometryHelper::SetAdjustCurvature+0x8ae9
STACK_COMMAND: ~0s; .ecxr ; kb
SYMBOL_STACK_INDEX: 1
SYMBOL_NAME: arma3!simul::base::GetRTTITypeInfo+2e50f
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: arma3
IMAGE_NAME: arma3.exe
DEBUG_FLR_IMAGE_TIMESTAMP: 55dc7939
FAILURE_BUCKET_ID: SOFTWARE_NX_FAULT_c0000005_arma3.exe!simul::base::GetRTTITypeInfo
BUCKET_ID: APPLICATION_FAULT_SOFTWARE_NX_FAULT_BAD_IP_arma3!simul::base::GetRTTITypeInfo+2e50f
ANALYSIS_SOURCE: UM
FAILURE_ID_HASH_STRING: um:software_nx_fault_c0000005_arma3.exe!simul::base::getrttitypeinfo
FAILURE_ID_HASH: {fb377c16-68fc-99a1-bdd5-b513327285e5}