Cirrostratus
CirrocumulusThe fact you lost management access indicates the TMM was probably restarting, assuming you managing via Self IP. If you were managing via management port, that becomes more strange. You should not have lost that access, so it is not normal.
Most of F5 software is written in C, so it is common get errors about C. I could not find any known issue with the lines you have.
I advise you to collect any core file and open support case.
This solution explains how to check for core files, and how to generate the md5 that you need when proving the core file to support.
https://support.f5.com/csp/article/K10062