- Make sure your output path is correct (i.e. you can't save tiffs to a GDB).
- You have a number of errors in your code, try the following:
actualrd = Raster('actualrd.tif') #Make template a Raster object
env.extent = actualrd #set the extent
env.cellSize = actualrd #set the cell size
env.overwriteOutput = True #set overwrite output to true
tempEuc = 'temp_dist.tif'
outEucDist = EucDistance(actualrd, 500)
outEucDist.save(tempEuc)
tempCon = r'temp_con.tif'
outCon = Con(((outEucDist >=0) & (actualrd == 1)), 1) #use outEucDist not tempEuc and actualrd Raster object not 'actualrd' string
outCon.save(tempCon)