The disassembler wants to parse an instruction that it finds valid and calls decodeUImmOperand which fails the assertion isUInt<N>(Imm). The instruction is found in a data section generated from random data.
There must be a bug in an instruction definition file and the immediate format specified.
Reproduce: dgemm.c.o.tar.gz
bin/llvm-objdump --mcpu=snitch --debug-vars -D dgemm.c.o