r - RStudio Working Directory Error -

updated question more details:

i not able open r workspace, , getting following error (in base r, rstudio shows first line of error , freezes):

error: value of 'set_attrib' must pairlist or null, not 'list' during startup - warning message: unable restore saved data in c:\r_library\a\.rdata 

other r workspaces loading corrupt .rdata file issue. r workspace half gb in size. working on windows machine (64-bit) r version 3.1.2.

my r running slow, , decided save workspace , relaod image. that's when error message started. due large data in environment, have handled more data before without issues.

there no information available on how fix issue. have unsaved code in directory, bare minimum want recover. advice useful.

try renaming file .rdata in r working directory. start r, , run

load("whatever renamed .rdata to").  

if still not work, try clicking on renamed r project file. should open workspace empty environment.