Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00001c3a480cbec0
Exception Note: EXC_CORPSE_NOTIFY
Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [0]
The problem appears to be a coding error and without access to the actual source code any more detail than that is not really possible.
I just downloaded the app from the App Store and the crash message I got in MacOS 10.13.4 beta 4 was…
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Which is essentially the same thing you got.
Notice that the last update to the app was in six years ago in 2012. I am surprised Apple has not been removed it as no longer supported.
You might take a look at
Universal Translator Pro ($2.99) which was updated in June 2017.