Since CCP removed bonus from rearguard systems, bot can work in front line and command systems only. If bot cannot find a system where to go (all visited), it will stop. Flying around between several systems w/o a work is a red flag imho. Try to select different time when to start bot or think about faction switch

I have run the program at various different times, yet this error still persists. I’ve also switched to other factions, but the exact same issue pops up again after just one or two days of operation.

If you using defender mode, switch to attacker. Defend mode is of low profit to start in most of systems. Remaining systems (usually 2-3 per side) not enough to stable work