GPG error, fail to fetch

[Acidrob13]

I'm getting GPG error: http//(whichever person hosting)signature release invalid NO DATA1 NO DATA2. I'm also getting; Failed to fetch (URL)/./ packages.bz2 sub process /bin/bzip2 returned an error code (2). If there's anything you could suggest Id really appreciate it .I'm new to this so i'm a little lost. Thanks

[lineskis]

You prOlLy have a bad repo. Theres an app in cydia tHat can fix this. I dobt remember name tho sorry

[cowburnator]

The app in Curia to fix this is called cyfix, there's also a few videos on YouTube telling you what to do

Sorry that should be cydia not curia

[serialtoon]

You can edit your own cydia list of sources if you want. They are under etc/sources.list.d/cydia.list

[mails4lami]

Please help: i'm having error message, sub-process/bin/bzip2 returned error code(2) some index file fail to download.
GPG error:
www.*************./Release:
the following signatures were invalid: NODATA1 NODATA2