I run W7 on a pc, with Bitdefender Total Security 2018. Only during Firefox automatic updates, the "Installer corrupted: invalid opcode" error message pops up in a dialogue box that Looks like a Windows dialogue box. I tried to upload jpg of it, but it timed out. The dialogue box looks like it's Windows with Setup in the upper left corner, a red X close button in upper right, and an OK button on the lower right. The updates seem to be successful, but just to be sure, every time this happens, I manually Check For Updates, and it immediately says :)Firefox is up to date. It seems to do this upon every auto update, which isn't very often. I've researched web, but see nothing about this error occurring only during Firefox updates. If Firefox is updating properly, I don't care about the error message. Is it updating properly? I appreciate your help.