When I try to create a custom tab, I am unable to and I get the following message: 
Validation Errors While Saving Record(s) 
There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was "This Developer Name already exists or has been previously used. Please choose a different name.". 
Click here to return to the previous page. 

In Tabs section of Setup there is no custom tab for this object. Also it cannot be found in profile settings or metadata. I tried SOQL query using tooling api, but I can't find the tab. The only place where it's mentioned is Rename Tabs and Labels in Setup, but that also doesn't do any help. The tab was certainly there before, but at some point it disappeared.

Has anyone had a similar issue? Any help would be greatly appreciated. Thanks!

When I try to create a custom tab, I am unable to and I get the following message: 
Validation Errors While Saving Record(s) 
There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was "This Developer Name already exists or has been previously used. Please choose a different name.". 
Click here to return to the previous page. 

In Tabs section of Setup there is no custom tab for this object. Also it cannot be found in profile settings or metadata. I tried SOQL query using tooling api, but I can't find the tab. The only place where it's mentioned is Rename Tabs and Labels in Setup, but that also doesn't do any help. The tab was certainly there before, but at some point it disappeared.

Has anyone had a similar issue? Any help would be greatly appreciated. Thanks!