RSLs on by default in Flex 4

I just wanted to post about this so I don’t forget.  I noticed that every time I opened a swf created using the Flex4 SDK, I would get a bunch of errors:

Error #2032: Stream Error. URL: file:///C:/home/projects/blah/textLayout_1.1.0.604.swf
Failed to load RSL textLayout_1.1.0.604.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/textLayout_1.1.0.604.swf
Warning: Ignoring ’secure’ attribute in policy file from http://fpdownload.adobe.com/pub/swz/crossdomain.xml.  The ’secure’ attribute is only permitted in HTTPS and socket policy files.  See http://www.adobe.com/go/strict_policy_files for details.
Error #2032: Stream Error. URL: file:///C:/home/projects/blah/osmf_flex.4.0.0.13495.swf
Failed to load RSL osmf_flex.4.0.0.13495.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/osmf_flex.4.0.0.13495.swf
Error #2032: Stream Error. URL: file:///C:/home/projects/blah/framework_4.1.0.16076.swf
Failed to load RSL framework_4.1.0.16076.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/framework_4.1.0.16076.swf
Error #2032: Stream Error. URL: file:///C:/home/projects/blah/spark_4.1.0.16076.swf
Failed to load RSL spark_4.1.0.16076.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/spark_4.1.0.16076.swf
Error #2032: Stream Error. URL: file:///C:/home/projects/blah/sparkskins_4.1.0.16076.swf
Failed to load RSL sparkskins_4.1.0.16076.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/sparkskins_4.1.0.16076.swf
Error #2032: Stream Error. URL: file:///C:/home/projects/blah/rpc_4.1.0.16076.swf
Failed to load RSL rpc_4.1.0.16076.swf
Failing over to RSL http://fpdownload.adobe.com/pub/swz/flex/4.1.0.16076/rpc_4.1.0.16076.swf

After doing a quick search, I found this post on  RSLs on by default in Flex 4.  Basically framework RSL’s are by default loaded by the swf file that is created when using the Flex4 SDK.  This greatly reduces the file size of the swf file.  If you were to turn it off by setting the following compiler argument:

-static-link-runtime-shared-libraries=true

Then the swf no longer tries to load those framework RSL’s and so you don’t see the errors.  But the file size of the swf jumps up significantly.  Just in a quick test I was working on, it jumped from about 86KB to about 593KB.  That is very significant.

So if you are testing stuff out and don’t want to see those errors, then set the above argument to true.  But if you are compiling a release version it’s probably best to have set to false to reduce file size.