After manually adding custom columns, for example, loading the wspcol table to a server, when selected "save and publish" in Schema Designer, an error "publish_schema failed in backend: Timeout waiting for reply after 60 seconds" comes up as shown below and the schema changes cannot be saved.
If we click on the "save and publish" again, the following error appears and the changes will not be saved.
Release: SDMU0M99000-14.1-Service Desk Manager-Full License and Higher
Component: Web Screen Painter
The error will appear if a column in the wspcol table referencing to non-existing table name, such as one that does not exist in the out of box schema or the wsptbl table.
e.g.
Non-existing table is specified as a SRel table of a custom SREL column.
A custom column added to non-existing table.
Remove a problematic column from the wspcol table, load it to the Service Desk Manager server, and then select "save and publish" in Schema Designer