Compatibility problem of Avast Free with Firefox and MPC HC?

[REDACTED]

I have used Avast Free for more than five years, but, Avast seems to have compatibility problem with Firefox and MPC HC recently, especially with Firefox.

Everytime I installed Avast Free, Firefox would crash directly, even if I have updated my firefox from Version 51 to Version 54. Don't kown if this was individual problem of my computer, or is already an universal problem.

Compatibility problem with MPC HC could be solved with MPC update from 1.7.10 to 1.7.11

Plattform Windows 7 with SP1

Problem is solved: with an update of IE from IE8 to IE11. What can I say about this?

Crash report (in German) :

[Rundvleeskroket]

What problems did you have with MPC-HC?

[Eddy]

avast does not have a problem with FireFox.
Must be something specific on your system that is causing the problem.

[REDACTED]

What problems did you have with MPC-HC?

also lead to crash

[REDACTED]

avast does not have a problem with FireFox.
Must be something specific on your system that is causing the problem.

Could be, but I could not figure out what kind of "something specific" caused this problem.
In fact, I had just reinstalled my operation system and there were no other software except Avast and Firefox. Moreover, in another try opera browser did not work as well if I had Avast in the system.

[Eddy]

Strange as both browsers work fine on mine system (W10 creator)

Have you search on the crash notification to see if gives (some) more information ?
Anything in one of the avast log files about this ?
Is there a minidump/crashreport created that could tell something more ?

[REDACTED]

Yes. I have attached it to my question, but pity just in German.

[Eddy]

What does it say in the "details" ?
Do you have other add-ons/plugins installed ?

[REDACTED]

It says: sorry a problem is found and Firefox crashed. Firefox will restart again to try to fix the problem (pity not successful)

No other add on, no other software, that why the problem comfused me so much.