@santiago1961 said in Opera suddenly closes with Citrix:
What Citrix product are you running? When you state that "Opera suddenly closes itself and reopen again", does it do that once each session, periodically, or in an endless loop?
Most of the time, that error code (0xc00000fd) is related to a program (or part/module of a program) being unable to be initiated. Usually, it's caused by file corruption or a coding issue in one of the programs that cause conflicts (stack overflows, etc). In your case and assuming that you're NOT referring to a Citrix extension installed into the browser, it sounds as if there's some kind of conflict between Opera and Citrix program code. That could be due to file corruption in either program or to a coding flaw in either program. Windows is faulting Opera as the cause, so it seems that something Opera is doing on your system at that point is conflicting with the OS's allocation of resources to Citrix. You could try running with Opera's extensions shut down to see if they are related to the problem, and you could try reinstalling Opera with Citrix running in the background. If neither of those work, you may be dealing with a genuine coding bug in either program.