We are sorry for the trouble. As described Acrobat XI pro is crashing and update is consistently fails.
Adobe Acrobat XI pro is an old and and EOL application and no longer supported. End of support means that Adobe no longer provides technical support, including product and/or security updates, for all derivatives of a product or product version (localized versions, minor upgrades, operating systems, dot and double-dot releases, and connector products).
Adobe strongly recommends that you upgrade to the latest versions of Adobe Acrobat DC and Adobe Acrobat Reader DC. By upgrading installations to the latest versions, you benefit from the latest functional enhancements and improved security measures.