Don't change CommonDefaultFormatTypes in $FrontEnd in install.m

[rolfmertig]

• Your Mathematica version

  11.2.0 for Microsoft Windows (64-bit) (September 11, 2017)

• Your FeynCalc version

  9.2.0

• Did you try to reinstall FeynCalc (stable version) using the automatic installer to make sure that you have the latest bugfixes?

  Yes

• Please provide a minimal working example that illustrates the problem. Please explain the difference between the current behavior and the expected behavior.

  The problem is that in installation.m the option CommonDefaultFormatTypes is set for $FrontEnd. And, since the explanation how to reset it is not correct in all version ( it should be CurrentValue[$FrontEnd, {CommonDefaultFormatTypes, "Output"}] = StandardForm) the problem is that for all subsequent Mathematica FrontEnd sessions the default output format type is TraditionalForm. The fix is to use CurrentValue[$FrontEndSession, {CommonDefaultFormatTypes, "Output"}] = TraditionalForm in install.m . Then any subequent Mathematica FrontEnd session will not be influenced by FeynCalc. (the other setting of $FrontEnd is probably just fine).

[vsht]

Should be now fixed. From now on the automatic installer will create FCConfig.m on the fly and set $FCTraditionalFormOutput=True; if TraditionalForm is desired. This will only modify the local front end session without touching the global Mathematica options.