Have spent about a day and a half now trying to figure this out. Use iThemes Builder software for WordPress site. Their tech folks don't know what else to tell me, and suggested I post here. Honestly don't know if this happened before 3.8.1 or with the update/upgrade, but after I did it, the Editor under the Appearance menu, as well as the Editor under Plugins, is no longer available. Here is what I've done in an attempt to fix:
1) Disabled all plugins
2) Reset plugins folder via FTP
3) Switched to a different "uncustomized" theme (mine had been working for about a year)
4) Updated to newest Builder Version
***** None of these worked -- so then I . . . *******
5) Downloaded a fresh WordPress 3.8.1 zip file
6) Unzipped on hard drive
7) Deleted the core files, wp-admin, and wp-includes folders on server and replaced with new fresh ones
8) Placed a default, plain .htaccess file in the web root directory
I may have even done some more things but don't remember now, but so far nothing has worked. I even checked with BlueHost to see if they were using caching anywhere in case I could have emptied it out. I've tried my site in both Firefox 28.0 and IE 8.0 (emptied cache). Quickly running out of ideas of what to try.
Any suggestions would be greatly appreciate. Thanks.