SwiftMessages: Crash on jailbroken iPod Touch 6G

Got the following crash:

iPod Touch 6G on 9.3.3

Crashed: com.apple.main-thread
EXC_BREAKPOINT 0x000000010170847c

Crashed: com.apple.main-thread
0  SwiftMessages                  0x10170847c IconStyle.image(theme : Theme) -> UIImage (Theme.swift:37)
1  ios                            0x1000fccdc static MessageManager.showInfo(String, body : String) -> () (MessageManager.swift:71)
2  UIKit                          0x18783d944 -[UIPresentationController transitionDidFinish:] + 1320
3  UIKit                          0x18796e418 -[_UICurrentContextPresentationController transitionDidFinish:] + 44
4  UIKit                          0x187840b3c __56-[UIPresentationController runTransitionForCurrentState]_block_invoke_2 + 188
5  UIKit                          0x187611114 -[_UIViewControllerTransitionContext completeTransition:] + 116
6  UIKit                          0x187610f00 -[UITransitionView notifyDidCompleteTransition:] + 252
7  UIKit                          0x1876109fc -[UITransitionView _didCompleteTransition:] + 1164
8  UIKit                          0x18761055c -[UITransitionView _transitionDidStop:finished:] + 124
9  UIKit                          0x18751bc28 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 312
10 UIKit                          0x18751bab0 -[UIViewAnimationState animationDidStop:finished:] + 108
11 QuartzCore                     0x184e75998 CA::Layer::run_animation_callbacks(void*) + 284
12 libdispatch.dylib              0x181dd547c _dispatch_client_callout + 16
13 libdispatch.dylib              0x181ddab84 _dispatch_main_queue_callback_4CF + 1844
14 CoreFoundation                 0x182340d50 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
15 CoreFoundation                 0x18233ebb8 __CFRunLoopRun + 1628
16 CoreFoundation                 0x182268c50 CFRunLoopRunSpecific + 384
17 GraphicsServices               0x183b50088 GSEventRunModal + 180
18 UIKit                          0x18754a088 UIApplicationMain + 204
19 ios                            0x1000ec280 main (AppDelegate.swift:24)
20 libdyld.dylib                  0x181e068b8 start + 4```