hi, that sounds like some leftover of adware on your system. though that's probably not directly related to firefox, you could try running scans of your system with some of the tools mentioned at Troubleshoot Firefox issues caused by malware

I looked at what you said but I'm not very good with computers, so I wasn't sure which thing to click. Will it bother anything if I just leave the error message and just keep clicking ok when it comes up?

hi, you could look at the "How do I get rid of malware?" section and run scans with "Malwarebytes' Anti-Malware Free" & "AdwCleaner". the error message indicates that there was some malicious file on your system that ran on startup (but is no longer in place), but i'd worry a bit what else is looming on your system...

Try to locate this item with the Autoruns utility. You can use the MSConfig program or the Autoruns utility to see what software is getting started (be cautious with disabling services).

• https://docs.microsoft.com/en-us/sysinternals/downloads/autoruns

See also:

• https://answers.microsoft.com/en-us/protect/forum/protect_other-protect_scanning/there-was-a-problem-starting-crickapp/8e3a6c8c-7842-454f-8dc7-bba667e8f9c2
• https://www.google.com/search?q="TB/APISupport"