User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8) Gecko/20051111 Firefox/1.5 Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8) Gecko/20051111 Firefox/1.5 i have tried to get 1.5 to run along side 1.0, but two things happen. first, if 1.0 is launched first 1.5 refuses to load stating that another instance is running, but appears to have crashed/not responding (this is untrue as i am quite able to use 1.0 during this time), it doesnt even offer the option to use/create another profile. secondly, if 1.5 is runing 1.0 presents the option to change profile, but there is no way to clone another profile (ie the default) nor is there any way to force 1.5 to swap profiles to allow 1.0 to use the default profile that it normally uses. however, should another profile be used (ie i have set up another profile called testing) it functions quite happlily. conclusion is that there is a small difference with the way in which 1.5 handels this as compared with 1.0 Reproducible: Always Steps to Reproduce: 1. launch 1.0 2. launch 1.5 3. watch 1.5 fail (and quit), continue using 1.0 normally -= OR =- 1. launch 1.5 2. launch 1.0 3. create profile 4. use both 1.5 and 1.0 side-by-side Actual Results: 1.5 either doesnt load or 1.0 has to create another profile dependent on the steps taken. Expected Results: 1.5 and 1.0 should work side-by-side and if necessary offer the user option to create/use a different profile. would be nice if a clone feature (in the profiles list) were available also allow the browser to duplicate the 'in use' profile seemlessly (hidden from user) and allow dynamic chanching of profiles during a session.

*** This bug has been marked as a duplicate of 264181 ***

this is not a duplicate of bug 264181. bug 264181 deals with instances of web based applications (i.e. the same web page stem, but with different data - two different users ids for say an online gallery or a bank). the deviation from this is through the additional "duplicates" forms a variant where two different instances of the SAME user application (firefox 1.5 rc3) can not be run if they have a common profile (as default). My bug report deals with different versions of firefox (i.e. firefox 1.0 and firefox 1.5 being run at the same time). firefox 1.5 does not allow you to change profiles when a profile is already in use as it did/does in 1.0. and therefore quits before one can change the profile!

You have to start with -P to select profile. This is probably a dupe of bug 287896 (where the workaround is also described).

Multiple instances of firefox cannt be used at the same time, regardless of the versions involved. *** This bug has been marked as a duplicate of 287896 ***