Updated to the official Isabelle 2020 release and corresponding AFP version.

.config

@@ -6,9 +6,9 @@ DOF_LATEST_DOI="10.5281/zenodo.3370483"
 DOF_GENERIC_DOI="10.5281/zenodo.3370482"
 #
 # Isabelle and AFP Configuration
-ISABELLE_VERSION="Isabelle2020-RC4: April 2020"
-ISABELLE_URL="https://isabelle.in.tum.de/website-Isabelle2020-RC4/"
-AFP_DATE="afp-2020-04-17"
+ISABELLE_VERSION="Isabelle2020: April 2020"
+ISABELLE_URL="https://isabelle.in.tum.de/website-Isabelle2020/"
+AFP_DATE="afp-2020-04-20"
 AFP_URL="https://www.isa-afp.org/release/"$AFP_DATE".tar.gz"
 #
 # Isabelle/DOF Repository Configuration

install

@@ -126,8 +126,6 @@ check_afp_entries() {
        fi
     done
     if [ "$missing" != "" ]; then 
-        echo "           Please install development version of AFP for Isabelle 2020 manually."
-        exit_error
         echo "           Trying to install AFP (this might take a few *minutes*) ...."
 	extract=""
 	for e in $missing; do